JP4902394B2 - Radio apparatus and radio link selection method - Google Patents

Description

  The present invention relates to a radio apparatus and a radio link selection method.

In recent years, a technique called cognitive radio communication in which one radio station performs communication using a plurality of radio communication media has been studied. Non-Patent Document 1 discloses mobile IP (Internet) when connecting to a plurality of wireless communication media (for example, a cellular system and a wireless local area network (wireless LAN) system) installed at different locations. A technique for performing seamless media switching by using (Protocol) is described. Non-Patent Document 2 describes wireless communication at the IP layer when a mobile router is mounted on an ITS (Intelligent Transport System) vehicle that connects to and communicates with a plurality of wireless communication media (for example, a cellular system and a wireless LAN system). A technique for switching media is described. Non-Patent Document 3 describes link aggregation in which a plurality of physical lines are aggregated and provided as one logical line.
Saito, et al., “Development of software for switching between different types of wireless communication media”, B-5-289, IEICE General Conference, 2003 Kashimura, et al. “Implementation of in-vehicle mobile router capable of switching communication media”, B-7-103, IEICE General Conference, 2003 IEEE802.3ad Standard (IEEE Computer Society LAN MAN Standards Committee) Aggregation of Multiple Link Segments, 2000.

  However, in cognitive radio communication, a technology for selecting a radio communication medium capable of obtaining stable communication quality while ensuring fair use among radio stations from among a plurality of radio communication media is an issue. Yes. For example, in a wireless LAN system, when a wireless station (access point station) of an access point and a terminal station perform cognitive wireless communication, when the access point station connects to a plurality of terminal stations (infrastructure mode), the terminal station It is not possible to appropriately determine which wireless communication medium should be used between access point stations.

  The present invention has been made in view of such circumstances, and its purpose is appropriate to obtain stable communication quality while ensuring fair use among wireless stations from among a plurality of wireless communication media. It is an object of the present invention to provide a radio apparatus and a radio link selection method that can select and use various radio communication media.

  In order to solve the above-described problems, a wireless device according to the present invention uses a plurality of wireless communication media and communicates for each wireless communication medium in a wireless device that establishes wireless links with a plurality of wireless stations. From the monitoring results of the wireless communication media monitoring means to be monitored, the wireless communication media monitoring means, the multiplicity calculation means for calculating the multiplicity of the wireless station for each wireless communication medium, and the monitoring results of the wireless communication media monitoring means A radio link usage rate calculating unit for calculating a radio link usage rate for each radio communication medium; a multiplicity of radio stations for each radio communication medium calculated by the multiplicity calculating unit; and the radio link usage rate calculating unit. Based on the wireless link usage rate for each wireless communication medium calculated in step 3, the wireless link of which wireless communication medium to use is determined for each wireless station of the communication partner. Link determination unit, the each radio communication medium, characterized by comprising a multiplicity informing means for informing a multiplicity of radio stations calculated in the multiplicity calculation means.

  A wireless device according to the present invention uses a plurality of wireless communication media, and in a wireless device that establishes a wireless link with one wireless station, wireless communication media monitoring means for monitoring communication for each wireless communication medium, From the monitoring result of the wireless communication media monitoring means, the wireless link usage rate calculating means for calculating the wireless link usage rate for each wireless communication medium, and the multiplicity of the notified radio station for each wireless communication medium is acquired. Based on multiplicity acquisition means, multiplicity of radio stations for each radio communication media acquired by the multiplicity acquisition means, and radio link usage rates for each radio communication medium calculated by the radio link usage rate calculation means And a radio link determination means for determining which radio communication medium radio link is used for each radio station of the communication partner.

  The radio apparatus according to the present invention is characterized in that the multiplicity of the radio stations is reported using a radio channel having a minimum channel usage rate.

  In the radio apparatus according to the present invention, the radio communication medium provided in the upper layer of the data link layer in the radio communication medium and used in units of IP packets or data link layer packets is selected according to the determination of the radio link selection control apparatus. Data link layer packet switch means is provided.

  A radio link selection method according to the present invention is a radio link selection method for establishing a radio link with a plurality of radio stations using a plurality of radio communication media, and monitoring communication for each radio communication medium. Calculating the radio station multiplicity for each radio communication medium from the monitoring result, calculating the radio link usage rate for each radio communication medium from the monitoring result, and calculating the calculated Based on the multiplicity of radio stations for each radio communication medium and the calculated radio link usage rate for each radio communication medium, the radio link of which radio communication medium is used for each radio station of the communication partner And a step of notifying the calculated multiplicity of the radio station for each of the radio communication media.

  A radio link selection method according to the present invention is a radio link selection method for establishing a radio link with one radio station using a plurality of radio communication media, and monitoring communication for each radio communication medium. A process of calculating a radio link usage rate for each radio communication medium, a process of obtaining the multiplicity of the broadcasted radio station for each radio communication medium, and the acquired Based on the multiplicity of radio stations for each radio communication medium and the calculated radio link usage rate for each radio communication medium, the radio link of which radio communication medium is used for each radio station of the communication partner And a process of performing.

  According to the present invention, it is possible to select and use an appropriate wireless communication medium from among a plurality of wireless communication media in order to obtain stable communication quality while ensuring fair use among wireless stations. Further, in the infrastructure mode, the terminal station can appropriately determine which wireless communication medium should be used between the access point stations.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration of a wireless device 1 according to an embodiment of the present invention. In the present embodiment, the wireless device 1 has both functions of an access point (AP) station and a terminal station of the wireless LAN system. The AP station is connected to a plurality of terminal stations (infrastructure mode). In the infrastructure mode, the AP station can establish a radio link with a plurality of terminal stations. The terminal station establishes a wireless link with one AP station.

  In FIG. 1, the wireless device 1 includes a plurality of wireless communication media wireless modules 11 </ b> A and 11 </ b> B, a packet switch 12, an IP (Internet Protocol) layer unit 13, and a control unit 14. The wireless module 11A is used when the wireless device 1 performs wireless communication as an AP station. The wireless module 11B is used when the wireless device 1 performs wireless communication as a terminal station. In the following description, the term “wireless module 11” will be used when there is no particular distinction between an AP station and a terminal station.

  Each wireless module 11 has functions of a physical (PHY) layer and a data link layer corresponding to each wireless communication medium. Examples of functions of the data link layer include MAC (Medium Access Control) and LLC (Logical Link Control). The wireless module 11 transmits and receives data link layer packets to and from the packet switch 12. The wireless module 11 performs wireless transmission and wireless reception of data link layer packets. In addition, the wireless module 11 may be provided with the same wireless communication media, but with different frequency channels.

  The packet switch 12 has a data link layer packet switching function. The packet switch 12 has a buffer provided corresponding to each of the wireless modules 11, and performs buffering of data link layer packets transmitted / received to / from the wireless module 11. The packet switch 12 has a conversion function for performing mutual conversion between the data link layer packet and the IP packet. The packet switch 12 transmits and receives IP packets to and from the IP layer unit 13.

  The control unit 14 controls the packet switch 12. Specifically, the wireless link of which wireless module 11 is to be used is determined for each IP packet, and the packet switch 12 is instructed.

  The packet switch 12 converts the IP packet received from the IP layer unit 13 into a data link layer packet by the conversion function, and outputs the data link layer packet to the wireless module 11 designated by the control unit 14. Further, the packet switch 12 converts the data link layer packet received from each wireless module 11 into an IP packet by the conversion function, and outputs the IP packet to the IP layer unit 13.

  At the time of transmission, the wireless module 11 converts the data link layer packet received from the packet switch 12 into a unique format of its own wireless communication medium and wirelessly transmits it. Further, at the time of reception, the data link layer packet of the specific format received wirelessly is converted into a data link layer packet of the common format and output to the packet switch 12.

  The IP layer unit 13 notifies the control unit 14 of information on input / output IP packets. The IP packet information to be notified includes, for example, address information (destination IP address, transmission source IP address, TCP (Transmission Control Protocol) port address, etc.), connection type (single connection, multiple connections), communication quality for IP flow. Request (transmission speed, QoS, etc.).

  The control unit 14 identifies an IP flow based on the address information notified from the IP layer unit 13 and determines a communication partner radio station. Then, the wireless module 11 of the wireless communication medium that can be used with the wireless station of the communication partner is selected for each IP packet from which wireless module 11 of the wireless communication medium is used. The selection result is instructed to the packet switch 12.

FIG. 2 is a schematic diagram illustrating an example of a cognitive radio communication system according to the present embodiment.
In FIG. 2, each wireless device (S1, D1, D2, D3, D4, D5) includes a wireless module 11 of three types of wireless communication media, and corresponds to each wireless communication medium. As examples of the three types of wireless communication media, in this embodiment, the IEEE (Institute of Electrical and Electronic Engineers) wireless access standard “IEEE802.16e” and the wireless LAN standard “IEEE802.11g” The description will be given with reference to “IEEE802.11j”. Each wireless device (S1, D1, D2, D3, D4) has an IEEE802.16e wireless module, an IEEE802.11g wireless module, and an IEEE802.11j wireless module.

  The wireless device (S1) has both functions of an AP station and a terminal station. The wireless device (S1) corresponds to the wireless device 1 of FIG. The wireless device (S1) includes an IEEE802.16e wireless module, an IEEE802.11g wireless module, and an IEEE802.11j wireless module for the AP station and the terminal station, respectively. The wireless devices (D1, D2, D3, D4) have the function of a terminal station (STA). The wireless device (D5) has the function of an AP station.

  The IEEE802.16e wireless module for the AP station of the wireless device (S1) establishes wireless links with the three wireless devices (D1, D2, D3). The IEEE802.11g wireless module for the AP station of the wireless device (S1) establishes wireless links with the two wireless devices (D1, D2). The wireless module of IEEE802.11j for the AP station of the wireless device (S1) has established a wireless link with one wireless device (D1).

  The IEEE802.16e wireless module for the terminal station of the wireless device (S1) establishes a wireless link with one wireless device (D5). None of the IEEE802.11g and IEEE802.11j wireless modules for the terminal station of the wireless device (S1) has established a wireless link. The IEEE802.16e wireless module of the wireless device (D5) establishes wireless links with the two wireless devices (S1, D4), respectively. The IEEE802.11g wireless module of the wireless device (D5) has established a wireless link with one wireless device (D4).

In the example of FIG. 2, the AP station (S1, D5) can know the multiplicity of the wireless module by monitoring its own wireless module.
The multiplicity of the wireless module means that when the wireless module has established a wireless link, either the wireless module or the wireless module of the other party that has established a wireless link with the wireless module. This is the maximum number of wireless stations among the number of wireless stations with which one wireless module has established a wireless link. In this embodiment, the multiplicity of the wireless module corresponds to the multiplicity of the wireless station for the wireless communication medium.

  The AP station is connected to a plurality of terminal stations, but the terminal station is connected to only one AP station. Therefore, the multiplicity of the radio module is equal to the number of terminal stations with which the radio module of the AP station has established a radio link. For example, the AP station (S1) monitors its own IEEE 802.16e radio module so that the IEEE 802.16e radio module has established radio links with three terminal stations (D1, D2, D3). I can know that. At this time, either the IEEE802.16e wireless module of the AP station (S1) or the IEEE802.16e wireless module of the wireless link establishment partner (D1, D2, D3) Among the numbers, the maximum number of wireless stations is “3”, which is the number of wireless stations with which the IEEE802.16e wireless module of the AP station (S1) has established a wireless link. On the other hand, even if the terminal stations (D1, D2, D3) monitor their own wireless modules, the AP station cannot know the number of other terminal stations other than itself with which the wireless link has been established. You cannot know the multiplicity of modules.

  FIG. 3 is a block diagram showing a configuration of the control unit 14 shown in FIG. FIG. 3 shows a characteristic part according to the present invention in the configuration of the control unit 14. The control unit 14 includes an AP station corresponding unit 14A that performs control for realizing the function of the AP station, and a terminal station corresponding unit 14B that performs control for realizing the function of the terminal station. FIG. 4 is a block diagram showing the configuration of the AP station corresponding unit 14A shown in FIG. FIG. 5 is a block diagram showing a configuration of the terminal station corresponding unit 14B shown in FIG.

First, the AP station corresponding unit 14A will be described with reference to FIG.
In FIG. 4, the wireless communication media monitoring unit 21A monitors communication for each AP station wireless module 11A. The multiplicity table generation unit 22A calculates the multiplicity for each wireless module 11A from the monitoring result of the wireless communication media monitoring unit 21A. The calculation result of the multiplicity is stored in the multiplicity table 23A. The radio link usage rate measuring unit 24AA measures the usage rate of each radio communication medium for each radio link from the monitoring result of the radio communication media monitoring unit 21A. The radio link determination unit 25A determines which radio communication medium is used based on the usage rate of each radio link measured by the radio link usage rate measurement unit 24A and the multiplicity table 23A. The beacon information transmitting unit 26 transmits the multiplicity of the wireless module stored in the beacon frame to each wireless module 11A.

  The wireless communication media monitoring unit 21A records for each wireless module 11A which terminal station the wireless link is established (wireless link connection information). At this time, whether or not the terminal station with which the radio link is established is in an active state (a state in which communication is immediately possible) may be recorded.

  Further, the radio communication media monitoring unit 21A records the actual use time of the radio link for each predetermined period for each radio communication medium. Here, when a plurality of wireless links are established for one wireless communication medium, the actual usage time is recorded for each wireless link. If there is only one wireless module 11A of the same wireless communication medium, only the wireless module 11A is set as a recording target of the wireless communication medium. If there are a plurality of wireless modules 11A of the same wireless communication media, all those wireless modules 11A are set as the recording targets of the wireless communication media. The actual use time of the radio link refers to the time when the radio link is actually used for packet transmission.

  The multiplicity table generator 22A generates a multiplicity table 23A based on the radio link connection information recorded by the radio communication media monitoring unit 21A. The multiplicity table generation unit 22A detects the terminal station of the radio link establishment partner in the radio link connection information for each radio module 11A. Alternatively, only the terminal station in the active state of the radio link establishment partner in the radio link connection information may be detected for each radio module 11A. The multiplicity table generator 22A calculates the number of detected terminal stations for each radio module 11A, and writes the calculation result in the multiplicity table 23A as the multiplicity of each radio module. In the multiplicity table 23A, the multiplicity table generation unit 22A writes the multiplicity of the radio module in the columns of all terminal stations with which radio links are established for one radio module.

  FIG. 6 shows a multiplicity table 23A of the AP station (S1) corresponding to the example of FIG. With regard to the IEEE 802.16e wireless module, a wireless link is established between three terminal stations: a terminal station (D1), a terminal station (D2), and a terminal station (D3). Accordingly, in the multiplicity table 23A, the multiplicity “3” is written in the fields of the IEEE 802.16e radio module and each terminal station (D1, D2, D3). Regarding the wireless module of IEEE802.11g, a wireless link is established between two terminal stations, the terminal station (D1) and the terminal station (D2). Accordingly, in the multiplicity table 23A, multiplicity “2” is written in the fields of the IEEE802.11g wireless module and each terminal station (D1, D2). Regarding the wireless module of IEEE802.11j, a wireless link is established between one terminal station of only the terminal station (D1). Accordingly, in the multiplicity table 23A, multiplicity “1” is written in the field of the wireless module of IEEE802.11j and the terminal station (D1).

  The wireless link usage rate measuring unit 24A uses the usage rate of each wireless communication medium for each wireless link based on the actual usage time of each wireless link for each fixed period recorded by the wireless communication media monitoring unit 21A for each wireless communication medium. Is calculated. The usage rate of the radio link is the actual usage time per unit time.

  The radio link determination unit 25A calculates a radio link evaluation value for each terminal station based on the usage rate of each radio link measured by the radio link usage rate measurement unit 24A and the multiplicity table 23A. Then, based on the evaluation value, it is determined which radio communication medium radio link is used.

The evaluation value of the radio link for each radio station is shown below.
The evaluation value X_Y_Z of the wireless link Z of the wireless module Y related to the wireless station X is expressed by the following equation. This evaluation value represents the load on the radio link.
Evaluation value X_Y_Z = (use rate of wireless link Z) × (multiplicity of wireless module Y)

  The radio link determination unit 25A determines the radio module 11A and the radio link that can obtain the minimum evaluation value for a certain terminal station as radio modules and radio links to be used.

  The control unit 14 uses the wireless module 11A to be used in units of IP packets according to the content determined by the wireless link determination unit 25A (information about which wireless module 11A and the wireless link are used with the communication partner terminal station). Select. Then, the selection result is instructed to the packet switch 12.

  The beacon information transmitting unit 26 transmits the multiplicity of the wireless module to each wireless module 11A based on the multiplicity table 23A. The beacon information transmitting unit 26 reads the multiplicity of each wireless module 11A from the multiplicity table 23A. In the example of FIG. 6, for example, the multiplicity of the wireless module of IEEE802.16e is “3”. The beacon information transmission unit 26 transmits the multiplicity of the wireless module read from the multiplicity table 23A to each wireless module 11A. The wireless module 11A stores the multiplicity of the wireless module received from the beacon information transmitting unit 26 at a predetermined position in the beacon frame. FIG. 7 shows a configuration example of the beacon frame 40 according to the present embodiment. In the example of FIG. 7, the multiplicity of the wireless module is stored at a position immediately before the last FCS (Frame Check Sequence) of the beacon frame 40. The beacon frame 40 is wirelessly transmitted in a broadcast format periodically. The terminal station can acquire the multiplicity of the wireless module by receiving the beacon frame 40.

Next, the terminal station corresponding unit 14B will be described with reference to FIG.
In FIG. 5, the wireless communication media monitoring unit 21B monitors communication for each wireless module 11B for terminal stations. The wireless communication media monitoring unit 21B monitors only the actual usage time of the wireless link. The radio communication media monitoring unit 21B records the actual use time of the radio link for each fixed period for each radio communication medium. This recording method is the same as that of the wireless communication media monitoring unit 21A.

  The wireless link usage rate measurement unit 24B uses the usage rate of each wireless communication medium for each wireless link based on the actual usage time of each wireless link for each fixed period recorded by the wireless communication media monitoring unit 21B for each wireless communication medium. Is calculated.

  The beacon information receiving unit 31 receives the multiplicity of the wireless module in the beacon frame received by the wireless module 11B from each wireless module 11B.

  The multiplicity table generator 22B generates a multiplicity table 23B based on the multiplicity of the wireless module received by the beacon information receiver 31. The multiplicity table generation unit 22B writes the multiplicity of the wireless module to the multiplicity table 23B for each wireless module 11B.

  FIG. 8 shows a multiplicity table 23B of the terminal station (D2) corresponding to the example of FIG. Since the multiplicity table 23B of the terminal station (D2) is generated based on the multiplicity of the wireless module in the beacon frame received from the AP station (S1), it is common with the multiplicity table 23A of the AP station (S1). It becomes. In FIG. 8, the multiplicity of the wireless module of IEEE802.16e is “3”, and the multiplicity of the wireless module of IEEE802.11g is “2”. This is shared with the multiplicity table 23A of FIG. In the example of FIG. 2, the terminal station (D2) does not receive the IEEE802.11j beacon frame because the wireless link of the IEEE802.11j wireless module has not been established between the AP stations (S1). For this reason, since the multiplicity of the wireless module of IEEE802.11j cannot be acquired, the field of the wireless module of IEEE802.11j in the multiplicity table 23B of FIG. 8 is blank (no information).

  The radio link determination unit 25B calculates the evaluation value of the radio link between the AP stations based on the usage rate of each radio link measured by the radio link usage rate measurement unit 24B and the multiplicity table 23B. Then, based on the evaluation value, it is determined which radio communication medium radio link is used. This determination method and the evaluation value of the radio link are the same as those of the radio link determination unit 25A.

  The radio link determination unit 25B determines the radio module 11B and the radio link from which the minimum evaluation value is obtained as the radio module and radio link used between the AP stations.

  The control unit 14 uses the wireless module 11B to be used in units of IP packets according to the content determined by the wireless link determination unit 25B (information about which wireless module 11B and the wireless link are used with the communication partner AP station). Select. Then, the selection result is instructed to the packet switch 12.

  As described above, according to the present embodiment, the data link layer packet switch for selecting the wireless communication medium to be used in units of IP packets is provided above the data link layer (MAC, LLC, etc.) in the wireless communication medium. Further, the wireless module and the wireless link that can obtain the minimum evaluation value are used based on the evaluation value (the load of the wireless link) including the usage rate of the wireless link and the multiplicity of the wireless module. Thereby, since the low-load radio link is preferentially used, it is possible to stabilize the communication quality while allowing each radio station to use the radio link fairly.

  In addition, since the multiplicity of the wireless module detected by the AP station is stored in a beacon frame and transmitted in a broadcast format, the terminal station can not know the wireless module from the received beacon frame. Can be known. Thereby, in the infrastructure mode, the terminal station can appropriately determine which radio communication medium should be used between the AP stations.

  The multiplicity of the wireless module is preferably transmitted using a beacon frame of a wireless channel with a minimum channel usage rate. This is because the use of a radio channel with the lowest channel usage rate increases the possibility that the terminal station normally receives the beacon frame and reliably transmits the multiplicity of the radio module to the terminal station. is there.

  Note that the terminal station may include only the time actually used for packet transmission by other terminal stations other than its own station in the actual use time of the radio link. In other words, the terminal station may record the actual usage time of the radio link excluding the time related to the packet related to the communication of the terminal station. The wireless module 11B of the terminal station receives a packet related to the communication of the terminal station and other packets. Therefore, the terminal station may use the time obtained by subtracting the time related to the packet related to the communication of the own station from the total actual use time of the radio link as the actual use time of the radio link. Packets related to the communication of the local station include a communication packet and a control packet related to the communication packet. For example, in the IEEE802.11 related standard, a DATA packet as a communication packet is delivered by a series of procedures using four types of packets (RTS, CTS, DATA, ACK). Packets (RTS, CTS, ACK) other than DATA packets are control packets for DATA packet delivery. Therefore, these four types of packets (RTS, CTS, DATA, ACK) related to the communication of the local station may be excluded from the target of the actual use time of the radio link.

Further, the above evaluation value can be modified. For example, the value obtained by the following equation may be the evaluation value X_Y_Z of the radio link Z of the radio module Y related to the radio station X.
Evaluation value X_Y_Z = (unused rate of wireless link Z) / (multiplicity of wireless module Y)
In this case, the wireless module and the wireless link that can obtain the maximum evaluation value are determined as the wireless module and the wireless link to be used.

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 design changes and the like within a scope not departing from the gist of the present invention.
For example, in the above-described embodiment, the wireless device 1 has the functions of both the AP station and the terminal station. Can be applied as well. In the case of a wireless device having only the function of an AP station, the wireless module only needs to be provided for the AP station, and only the AP station corresponding unit 14A in FIG. It becomes unnecessary. In the case of a wireless device having only the function of a terminal station, the wireless module only needs to be provided for the terminal station, and only the terminal station corresponding unit 14B in FIG. It becomes unnecessary.

  Further, the control unit 14 may select a wireless communication medium to be used in units of data link layer packets and instruct the packet switch 12.

It is a block diagram which shows the structure of the radio | wireless apparatus 1 which concerns on one Embodiment of this invention. It is the schematic which shows the example of the cognitive radio | wireless communications system which concerns on the same embodiment. It is a block diagram which shows the structure of the control part 14 shown in FIG. It is a block diagram which shows the structure of 14 A of AP station corresponding parts shown in FIG. It is a block diagram which shows the structure of the terminal station corresponding | compatible part 14B shown in FIG. It is a structural example of the multiplicity table 23A of AP station which concerns on one Embodiment of this invention. It is an example of composition of beacon frame 40 concerning one embodiment of the present invention. It is an example of a structure of the multiplicity table 23B of the terminal station which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wireless device, 11A, 11B ... Wireless module, 12 ... Packet switch, 13 ... IP layer part, 14 ... Control part, 14A ... AP station corresponding part, 14B ... Terminal station corresponding part 14B, 21A, 21B ... Wireless communication media Monitoring unit, 22A, 22B ... Multiplicity table generation unit, 23A, 23B ... Multiplicity table, 24A, 24B ... Radio link usage rate measurement unit, 25A, 25B ... Radio link determination unit, 26 ... Beacon information transmission unit, 31 ... Beacon information receiving unit, 40 ... Beacon frame

Claims (6)

In a wireless device that uses a plurality of wireless communication media and establishes a wireless link with a plurality of wireless stations,
Wireless communication medium monitoring means for monitoring communication for each wireless communication medium;
From the monitoring result of the wireless communication media monitoring means, multiplicity calculation means for calculating the multiplicity of the radio station for each wireless communication medium,
From the monitoring result of the wireless communication media monitoring means, a wireless link usage rate calculating means for calculating a wireless link usage rate for each wireless communication medium;
Based on the multiplicity of the radio station for each radio communication medium calculated by the multiplicity calculation means and the radio link usage rate for each radio communication medium calculated by the radio link usage rate calculation means, Radio link determination means for determining which radio communication medium radio link is used for each station;
Multiplicity notification means for reporting the multiplicity of the wireless station calculated by the multiplicity calculation means for each wireless communication medium;
A wireless device comprising: In a wireless device that uses a plurality of wireless communication media and establishes a wireless link with one wireless station,
Wireless communication medium monitoring means for monitoring communication for each wireless communication medium;
From the monitoring result of the wireless communication media monitoring means, a wireless link usage rate calculating means for calculating a wireless link usage rate for each wireless communication medium;
Multiplicity acquisition means for acquiring the multiplicity of the notified radio station for each wireless communication medium;
Based on the multiplicity of the radio station for each radio communication medium acquired by the multiplicity acquisition means and the radio link usage rate for each radio communication medium calculated by the radio link usage rate calculation means, Radio link determination means for determining which radio communication medium radio link is used for each station;
A wireless device comprising:   The radio apparatus according to claim 1 or 2, wherein the multiplicity of the radio station is reported using a radio channel having a minimum channel usage rate.   Data link layer packet switch means is provided above the data link layer in the wireless communication medium and selects a wireless communication medium to be used in units of IP packets or data link layer packets according to the determination of the wireless link selection control device. The wireless device according to claim 1, wherein the wireless device is a wireless device. A radio link selection method for establishing a radio link with a plurality of radio stations using a plurality of radio communication media,
A process of monitoring communication for each wireless communication medium;
From the monitoring result, for each wireless communication medium, calculating the multiplicity of the wireless station,
From the monitoring result, a process of calculating a wireless link usage rate for each wireless communication medium;
Based on the calculated multiplicity of radio stations for each radio communication medium and the calculated radio link usage rate for each radio communication medium, the radio link of which radio communication medium is determined for each radio station of the communication partner. The process of deciding whether to use,
For each wireless communication medium, the process of notifying the calculated multiplicity of the wireless station,
A method of selecting a radio link, comprising: A radio link selection method for establishing a radio link with one radio station using a plurality of radio communication media,
A process of monitoring communication for each wireless communication medium;
From the monitoring result, for each wireless communication medium, calculating a wireless link usage rate,
For each wireless communication medium, the process of obtaining the multiplicity of the notified wireless station,
Based on the obtained multiplicity of radio stations for each radio communication medium and the calculated radio link usage rate for each radio communication medium, which radio communication medium radio link is determined for each radio station of the communication partner. The process of deciding whether to use,
A method of selecting a radio link, comprising:

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