WO2016117013A1 - Wireless base-station apparatus, wireless communication system, and communication control method - Google Patents

Abstract

A wireless base-station apparatus includes an occupancy-rate calculation unit and a first control unit. The occupancy-rate calculation unit calculates, for each of wireless terminal devices connected to the wireless base-station apparatus, a wireless-space occupancy rate of frames transmitted and received between the wireless base-station apparatus and the wireless terminal devices. The first control unit specifies, using the wireless-space occupancy rate calculated by the occupancy-rate calculation unit, a wireless terminal device among the wireless terminal devices connected to the wireless base-station apparatus, and performs control to disconnect the connection between the specified wireless terminal device and the wireless base-station apparatus.

Description

Radio base station apparatus, radio communication system, and communication control method

The present invention relates to a radio base station apparatus, a radio communication system, and a communication control method.

In a wireless communication system, there is a random access method as one of access methods for a plurality of wireless terminal devices to connect to a wireless base station device using predetermined wireless resources (time and frequency). In the random access method, a plurality of wireless terminal devices connected to a wireless base station device share a wireless channel. An example of the random access method is CarrierCarSense Multiple Access / Collision Avoidance (CSMA / CA). CSMA / CA is adopted in Wireless Local Area Network (LAN) standardized by Institute of Electrical and Electronics Electronics (IEEE) 802.11 Project. In CSMA / CA, devices that transmit frames (wireless base station devices and wireless terminal devices) check whether other devices are using the wireless channel based on the strength of received power before transmitting frames ( Career sense). When it is confirmed that another device is using the wireless channel, the device that transmits the frame postpones transmission of the frame until the wireless channel becomes unused.

The consumption of radio resources increases as the number of radio terminal apparatuses connected to the radio base station apparatus, that is, the number of connected terminals increases. Also, the amount of radio resource consumption increases as the amount of traffic transmitted from the transmission source device (wireless base station device or wireless terminal device) to the destination device (wireless terminal device or wireless base station device) increases. For example, in a communication with a large amount of data such as video streaming, the amount of traffic is large compared to a communication with a small amount of data such as a text message.

In a wireless communication system using the random access method, when the amount of wireless resources consumed increases due to an increase in the number of connected terminals and traffic volume, the transmission waiting time for transmitting a frame when the wireless channel is not used increases. In addition, if the amount of radio resources increases due to an increase in the number of connected terminals and traffic, the number of frames that are retransmitted increases because the probability of frame collision increases due to multiple devices transmitting frames simultaneously by chance. Will increase. As a result, the throughput of the wireless communication system decreases. When the throughput further decreases with the increase in the consumption of radio resources, a congestion state occurs. The congestion state may cause the entire wireless communication system to be down such that all communication is interrupted.

The following traffic control devices are known. That is, the traffic control device is located between a wireless LAN system composed of a base station and a wireless LAN terminal, and a backbone network, and measures the amount of traffic passing through the own station and guarantees the bandwidth of specific traffic. Means. The traffic control device includes a base station table that stores a wireless channel used by a base station for communication with a subordinate wireless LAN terminal, and a terminal table that stores an identifier of the subordinate wireless LAN terminal for each base station. . The traffic control device aggregates traffic for which the bandwidth is guaranteed with reference to the base station table and the terminal table for each wireless channel, and determines the base station for the wireless LAN terminal according to the comparison result of the aggregated value of each wireless channel. Means for instructing reselection are provided.

Also, the following wireless LAN base stations are known. That is, the wireless LAN base station (apparatus) includes a reception processing unit that performs reception processing, a traffic control unit that controls traffic, and a bandwidth management unit that manages bandwidth. The reception processing unit includes a first calculation unit and a second determination function. The first calculation means determines the validity of the communication request. The second determination function is occupied by first calculation means for calculating a bandwidth or time required for wireless communication of the wireless terminal and a plurality of wireless terminals that have already approved reception of communication requests from other wireless terminals. The value calculated by the second calculating means for calculating the surplus bandwidth or surplus time from the sum of the bandwidth or time is compared. Then, the second determination function determines whether to accept a communication request from the wireless terminal. The traffic control unit includes a traffic monitoring unit that monitors traffic and a traffic control execution unit that executes traffic control.

Furthermore, the following mobile communication systems are known. That is, the mobile communication system includes means for measuring the traffic amount in each cell. In addition, the mobile communication system is configured to change the cell size from the narrower cell size to the original cell size depending on whether or not the traffic amount is lower and the first threshold value for changing the cell size to a smaller cell size depending on whether or not the traffic amount exceeds. Means for storing and holding a second threshold value smaller than the first threshold value. The mobile communication system automatically changes the cell size of each cell according to the traffic volume measured sequentially. Since the first and second threshold values are individually determined between the cell sizes, the cell size is not frequently changed even if the traffic amount is around the first threshold value. In addition, when the operation of the cell is stopped, the area of the stopped cell is covered with an adjacent cell so that the service in the area can be continued.

JP 2003-60663 A JP 2007-74210 A JP 2006-101442 A

The problem to be solved by the invention is to improve the throughput in the radio communication system and prevent the occurrence of congestion in the radio communication system.

According to one aspect of the embodiment, the radio base station apparatus includes an occupancy rate calculation unit and a first control unit. The occupancy ratio calculation unit calculates a radio space occupancy ratio of frames transmitted and received between the radio base station apparatus and each radio terminal apparatus connected to the radio base station apparatus for each radio terminal apparatus. The first control unit identifies a radio terminal device using the radio space occupancy calculated by the occupancy rate calculation unit among the radio terminal devices connected to the radio base station device, and the identified radio terminal device and the radio Control to disconnect the connection with the base station apparatus.

According to the radio base station apparatus according to one aspect of the embodiment, the throughput in the radio communication system is improved, and the occurrence of a congestion state in the radio communication system can be prevented.

1 is an exemplary configuration diagram of a communication network system including a wireless communication system according to a first embodiment. It is an exemplary functional block diagram of the radio base station apparatus according to the first embodiment. It is an example figure of a connection terminal storage table. It is an example figure of a traffic amount storage table. It is an example figure of an occupation rate storage table. It is an exemplary hardware block diagram of the radio base station apparatus according to the first embodiment. It is a flowchart of the example load distribution process which the wireless base station apparatus according to 1st Embodiment performs. It is a flowchart of the example load distribution process which the wireless base station apparatus according to 1st Embodiment performs. It is an exemplary functional block diagram of the radio base station apparatus according to 2nd Embodiment. It is an example figure of an adjacent base station storage table. It is a flowchart of the example load distribution process which the wireless base station apparatus according to 2nd Embodiment performs. It is a flowchart of the example load distribution process which the wireless base station apparatus according to 2nd Embodiment performs. It is a flowchart of the example load distribution process which the wireless base station apparatus according to 2nd Embodiment performs. It is an example functional block diagram of the radio base station apparatus according to 3rd Embodiment. It is an example figure of another area terminal storage table. It is an exemplary functional block diagram of the control apparatus according to 3rd Embodiment. It is an example figure of the connection terminal storage table with which the control apparatus according to 3rd Embodiment is provided. It is an example figure of the occupation rate storage table with which the control apparatus according to 3rd Embodiment is provided. It is an example figure of the traffic amount storage table with which the control apparatus according to 3rd Embodiment is provided. It is an example hardware block diagram of the control apparatus according to 3rd Embodiment. It is a flowchart of the example load distribution process which the control apparatus according to 3rd Embodiment performs. It is a flowchart of the example load distribution process which the control apparatus according to 3rd Embodiment performs. It is a flowchart of the example load distribution process which the control apparatus according to 3rd Embodiment performs.

Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is an exemplary configuration diagram of a communication network system including a wireless communication system according to the first embodiment. As shown in FIG. 1, a communication network system 100 includes a second wireless communication system 400 including first wireless communication systems 200-1 to 200-N and a control device 300, a wide area network (WAN) )) 500. Here, the symbol “N” represents an integer of 2 or more. For example, the second wireless communication system 400 may be a wireless communication system compatible with a wireless LAN standardized by the IEEE 802.11 Project.

The first wireless communication systems 200-1 to 200-N are wireless communication systems that use a predetermined random access method such as CSMA / CA. First radio communication systems 200-1 to 200-N are examples of the radio communication system according to the first embodiment. The radio communication system according to the first embodiment includes one radio base station apparatus and a plurality of radio terminal apparatuses connected to the radio base station apparatus. In the example shown in FIG. 1, the first radio communication system 200-1 includes a radio base station device 600-1 and radio terminal devices 700-1-1 to 700-1-L. Further, the first radio communication system 200-N includes a radio base station device 600-N and radio terminal devices 700-N-1 to 700-NM. Here, the symbol “L” and the symbol “M” represent an integer of 2 or more. In the following description, the first radio communication systems 200-1 to 200-N are referred to as the first radio communication system 200 unless otherwise distinguished. Radio base station apparatuses 600-1 to 600-N are described as radio base station apparatus 600 unless otherwise distinguished. The wireless terminal devices 700-1-1 to 700-NM are referred to as wireless terminal devices 700 unless otherwise distinguished.

The radio base station apparatus 600 and the radio terminal apparatus 700 included in each first radio communication system 200 share radio resources such as radio channels according to a predetermined random access scheme. In the wireless LAN, each first wireless communication system 200 is referred to as a basic service set (BSS). The second wireless communication system 400 including a plurality of BSSs such as the first wireless communication systems 200-1 to 200-N is called an extended service set (ESS).

The radio base station apparatus 600 is an apparatus that is connected to the radio terminal apparatus 700 existing in a communication area covered by the radio base station apparatus 600 and transmits / receives data to / from the connected radio terminal apparatus 700. Radio base station apparatus 600 may be an apparatus called an access point, for example.

The wireless terminal device 700 is a device that is connected to the wireless base station device 600 and transmits / receives data to / from the connected wireless base station device 600. In the example shown in FIG. 1, radio terminal apparatuses 700-1-1 to 700-1-L are connected to radio base station apparatus 600-1, and radio terminal apparatuses 700-N-1 to 700-NM are wireless. Connect to base station apparatus 600-N. The wireless terminal device 700 is, for example, a multi-function mobile phone called a smartphone and a portable computer called a tablet personal computer (PC).

The radio base station apparatus 600 notifies the radio terminal apparatus 700 of the presence of the radio base station apparatus 600 by transmitting a beacon signal including an identifier of the radio base station apparatus 600 at predetermined time intervals. The wireless terminal device 700 receives the beacon signal transmitted from each wireless base station device 600 when the wireless terminal device 700 is powered on, for example. For each received beacon signal, the wireless terminal device 700 measures the strength of received power such as ReceiverReSignal Strength Indicator (RSSI). Then, the wireless terminal device 700 determines a connection with the wireless base station device 600 that has transmitted a beacon signal with high received power strength, and transmits a connection request signal to the wireless base station device 600. Radio base station apparatus 600 receives the connection request signal transmitted from radio terminal apparatus 700, and transmits a connection response signal indicating whether or not to allow connection with radio terminal apparatus 700 to radio terminal apparatus 700. When the wireless terminal device 700 receives a connection response signal indicating that the connection is permitted from the wireless base station device 600, a connection between the wireless terminal device 700 and the wireless base station device 600 is established. When the connection is established, the wireless terminal device 700 communicates with another wireless terminal device 700 and a communication device (not shown) existing on the wide area communication network 500 side via the connected wireless base station device 600.

Also, the reception power of the beacon signal transmitted from the connected wireless base station device 600 is changed by the movement of the wireless terminal device 700 or the change in the reception environment of the signal (radio wave) transmitted from the wireless base station device 600. In some cases, the strength is less than a predetermined threshold value after connection establishment. When such a case occurs, the radio base station apparatus 600 to which the radio terminal apparatus 700 is connected may be changed by the first connection method as described below. That is, the wireless terminal device 700 receives a beacon signal transmitted from each of the other wireless base station devices 600 in the second wireless communication system 400. Then, the wireless terminal device 700 measures the strength of received power for each received beacon signal. The wireless terminal device 700 determines that another wireless base station device 600 that has transmitted a measured beacon signal with high received power strength is a wireless base station device 600 whose connection is changed from the connected wireless base station device 600. To do. Then, the wireless terminal device 700 tries to change the connection from the currently connected wireless base station device 600 to the determined wireless base station device 600.

The control device 300 is a device that is connected to each wireless base station device 600 included in the second wireless communication system 400 in a wired manner and manages each connected wireless base station device 600. The control device 300 may be a device called a wireless LAN controller or a wireless LAN switch. The wide area communication network 500 is a communication network that connects the second wireless communication system 400 and another wireless communication system (not shown).

Note that FIG. 1 only shows an example of a communication network system including a wireless communication system according to the first embodiment. For example, in the example illustrated in FIG. 1, the first wireless communication system 200 is connected to the wide area communication network 500 through the control device 300. However, the second wireless communication system 400 may not include the control device 300, and the first wireless communication system 200 may be directly connected to the wide area communication network 500.

In the first embodiment, the radio base station apparatus 600 performs control so that the load applied to the radio base station apparatus 600 is distributed to other radio base station apparatuses 600 included in the second radio communication system 400. Since the load on the radio base station apparatus 600 is distributed, the consumption of radio resources shared by the radio base station apparatus 600 and the radio terminal apparatus 700 is reduced. As a result, the throughput in the first radio communication system 200 sharing the radio resources is improved, and the occurrence of a congestion state in the first radio communication system 200 is prevented.

FIG. 2 is an exemplary functional configuration diagram of the radio base station apparatus according to the first embodiment. As shown in FIG. 2, the radio base station apparatus 600 includes an antenna 601, a beam control unit 602 as an example of a second control unit, a radio reception processing unit 603, a frame reception processing unit 604, an upper layer processing unit 605, and A wide area network side interface 606 is included. Radio base station apparatus 600 further includes a frame generation unit 607 and a radio transmission processing unit 608. The radio base station apparatus 600 includes a connection terminal monitoring unit 609, a connection terminal storage unit 610, a traffic volume measurement unit 611, a traffic volume storage unit 612, an occupancy rate calculation unit 613, an occupancy rate storage unit 614, and a first control unit. An example load distribution control unit 615 is further included.

The radio reception processing unit 603 receives a radio signal (radio wave) transmitted from the radio terminal device 700 via the antenna 601 and the beam control unit 602. The wireless reception processing unit 603 extracts a frame transmitted from the wireless terminal device 700 by processing the received wireless signal. The frame extracted by the wireless reception processing unit 603 is a frame according to a predetermined communication standard of the first wireless communication system 200, for example, a frame according to a communication standard standardized by IEEE802.11 project. The wireless reception processing unit 603 transmits the extracted frame to the frame reception processing unit 604.

The frame reception processing unit 604 receives the frame extracted by the wireless reception processing unit 603. The frame reception processing unit 604 extracts various data included in the frame by processing the received frame. The various data extracted by the frame reception processing unit 604 includes transfer data (packet) that is a data body included in the frame, an identifier of the frame transmission source device, and an identifier of the frame destination device. Each identifier of the transmission source device and the destination device is, for example, a Media Access Control (MAC) address. The frame transmission source device is, for example, a wireless terminal device 700 connected to the wireless base station device 600. The frame reception processing unit 604 transmits the extracted transfer data to the upper layer processing unit 605. Also, the frame reception processing unit 604 transmits the extracted identifier of the transmission source device to the connection terminal monitoring unit 609.

The upper layer processing unit 605 receives the transfer data extracted by the frame reception processing unit 604. The upper layer processing unit 605 extracts the identifiers of the transmission source device and the destination device of the transfer data by processing the received transfer data. Each extracted identifier is, for example, an Internet Protocol (IP) address. The extracted identifier of the transmission source device is, for example, the identifier of the wireless terminal device 700 that transmitted the transfer data. The identifier of the extracted destination device is, for example, an identifier of a wireless terminal device 700 other than the wireless terminal device 700 that transmitted the transfer data, or an identifier of a communication device (not shown) on the wide area network 500 side. The upper layer processing unit 605 transmits the transfer data to the wide area communication network side interface 606 together with the extracted identifiers of the transmission source device and the destination device.

The wide area network side interface 606 receives the transfer data, the identifier of the transfer data transmission source device, and the identifier of the transfer data destination device from the upper layer processing unit 605. The wide area network interface 606 generates a frame including the identifier of the frame transmission source device, the identifier of the frame destination device, and the received transfer data. The frame generated by the wide area network side interface 606 is a frame according to a predetermined communication standard on the wide area network 500 side such as the control device 300, for example, an Ethernet (registered trademark) format frame. The identifier of the frame transmission source device is generated based on the identifier of the transfer data transmission source device. The identifier of the destination device of the frame is generated based on the identifier of the destination device of the transfer data. In the communication network system 100 illustrated in FIG. 1, the frame destination device is the control device 300. The wide area network side interface 606 converts the received frame into an electrical signal, and transmits the converted electrical signal to the control device 300.

Also, the wide area network side interface 606 receives the electrical signal transmitted from the control device 300. The wide area network side interface 606 extracts the frame transmitted from the control device 300 by processing the received electrical signal. The frame extracted by the wide area network side interface 606 is a frame in accordance with a predetermined communication standard on the wide area network 500 side such as the control device 300. The wide area network side interface 606 extracts various data from the extracted frame. The various data extracted by the wide area network side interface 606 includes transfer data (packet) which is a data body included in the frame, an identifier of the frame transmission source device, and an identifier of the frame destination device. Each identifier of the frame transmission source device and destination device is, for example, a MAC address. In the communication network system 100 shown in FIG. 1, the frame transmission source device is the control device 300. The wide area network side interface 606 transmits the extracted transfer data to the upper layer processing unit 605.

The upper layer processing unit 605 receives the transfer data extracted by the wide area communication network side interface 606. The upper layer processing unit 605 extracts the identifiers of the transmission source device and the destination device of the transfer data by processing the received transfer data. Each extracted identifier is, for example, an IP address. The extracted identifier of the transmission source device is, for example, the identifier of the communication device on the wide area communication network 500 side. The extracted identifier of the destination device is, for example, the identifier of the wireless terminal device 700. The upper layer processing unit 605 transmits the transfer data to the frame generation unit 607 together with the extracted identifiers of the transmission source device and the destination device.

The frame generation unit 607 receives the transfer data, the identifier of the transfer data transmission source device, and the identifier of the transfer data destination device from the upper layer processing unit 605. The frame generation unit 607 generates a frame including the identifier of the frame transmission source device, the identifier of the frame destination device, and the received transfer data. The frame generated by the frame generation unit 607 is a frame in accordance with a predetermined communication standard of the first wireless communication system 200. Each identifier of the frame transmission source device and destination device is, for example, a MAC address. The identifier of the frame transmission source device is generated based on the identifier of the transmission data transmission source device. The identifier of the frame destination device is generated based on the identifier of the destination device of the transfer data. The frame destination device is, for example, the wireless terminal device 700. The frame generation unit 607 transmits the generated frame to the wireless transmission processing unit 608. Further, the frame generation unit 607 transmits the identifier of the destination device of the generated frame to the connection terminal monitoring unit 609.

The wireless transmission processing unit 608 receives the frame generated by the frame generation unit 607. The wireless transmission processing unit 608 generates a wireless signal by processing the received frame. The radio transmission processing unit 608 transmits the generated radio signal to a destination device such as the radio terminal device 700 via the beam control unit 602 and the antenna 601.

The connected terminal monitoring unit 609 monitors the wireless terminal device 700 that is connected to the wireless base station device 600. In the following description, “wireless terminal apparatus 700 connected to radio base station apparatus 600” may be referred to as a connected terminal apparatus for convenience.

Specifically, the connected terminal monitoring unit 609 stores the identifier of the connected wireless terminal device 700 in the connected terminal storage unit 610 every time a connection between the wireless base station device 600 and the wireless terminal device 700 is established. Let FIG. 3 is an example of a connection terminal storage table. The connected terminal storage unit 610 stores the identifier of the wireless terminal device 700 connected to the wireless base station device 600 in the form of a connected terminal storage table 6101 as shown in FIG. The connection between the radio base station apparatus 600 and the radio terminal apparatus 700 is established by, for example, transmitting / receiving an association request frame and an association response frame. The association response frame transmitted by radio base station apparatus 600 includes an identifier of radio terminal apparatus 700 that is the destination apparatus of the association response frame. That is, the frame generation unit 607 generates an association response frame including the identifier of the wireless terminal device 700 with which the connection with the wireless base station device 600 is established as the identifier of the destination device. The connected terminal monitoring unit 609 receives the identifier of the wireless terminal device 700 with which the connection with the wireless base station device 600 is established from the frame generating unit 607, and stores the received identifier in the connected terminal storage unit 610.

Also, the connected terminal monitoring unit 609 deletes the identifier of the disconnected wireless terminal device 700 from the connected terminal storage unit 610 every time the connection between the wireless base station device 600 and the wireless terminal device 700 is disconnected. The connection between the radio base station apparatus 600 and the radio terminal apparatus 700 is disconnected, for example, when the radio terminal apparatus 700 transmits an association cancellation frame to the radio base station apparatus 600. The association cancellation frame transmitted by the wireless terminal device 700 includes an identifier of the wireless terminal device 700 that is the transmission source device of the association cancellation frame. That is, the frame reception processing unit 604 receives an association cancellation frame including the identifier of the wireless terminal device 700 that is disconnected from the wireless base station device 600 as the identifier of the transmission source device. The connected terminal monitoring unit 609 receives the identifier of the wireless terminal device 700 that is disconnected from the wireless base station device 600 from the frame reception processing unit 604, and deletes the received identifier from the connected terminal storage unit 610.

Furthermore, the connection terminal monitoring unit 609 receives the identifier of the transmission source device transmitted from the frame reception processing unit 604. The connection terminal monitoring unit 609 checks the received identifier of the transmission source device with the identifier of the connection terminal device stored in the connection terminal storage unit 610. As a result of the collation, when the received identifier of the transmission source device is the identifier of the connection terminal device, the connection terminal monitoring unit 609 uses the received transmission source device identifier as the identifier of the connection terminal device, and the traffic volume measurement unit 611 and It transmits to the occupation rate calculation unit 613.

Also, the connection terminal monitoring unit 609 receives the identifier of the destination device of the generated frame from the frame generation unit 607 that generated the frame including the transfer data received from the upper layer processing unit 605. The connection terminal monitoring unit 609 compares the received identifier of the destination device with the identifier of the connection terminal device stored in the connection terminal storage unit 610. As a result of the collation, when the received identifier of the destination device is the identifier of the connecting terminal device, the connecting terminal monitoring unit 609 uses the received identifier of the destination device as the identifier of the connecting terminal device and the traffic amount measuring unit 611 and the occupation rate It transmits to the calculation part 613.

The traffic volume measuring unit 611 measures the traffic volume within a predetermined time for each connected terminal device. The amount of traffic to be measured is the amount of traffic that a specific connection terminal device transmits to the radio base station device 600 within a predetermined time and the traffic that the radio base station device 600 transmits to a specific connection terminal device within a predetermined time Is the sum of The traffic amount measuring unit 611 stores the measured traffic amount in the traffic amount storage unit 612 for each connection terminal device. FIG. 4 is an example of a traffic volume storage table. The traffic volume storage unit 612 stores the measured traffic volume for each connected terminal device in the format of a traffic volume storage table 6121 as shown in FIG.

Specifically, the traffic volume measuring unit 611 receives the identifier of the connected terminal device transmitted from the connected terminal monitoring unit 609. In addition, the traffic amount measurement unit 611 receives, from the frame reception processing unit 604, transfer data in a frame that includes the received identifier as an identifier of the frame transmission source device. The traffic amount measuring unit 611 measures the data amount of the received transfer data as the traffic amount transmitted to the radio base station device 600 by the connection terminal device indicated by the received identifier. The traffic volume measuring unit 611 stores the measured data volume in the traffic volume storage unit 612 in association with the received identifier of the connected terminal device. The traffic amount measuring unit 611 repeats the above-described processing every time the transfer data is received from the frame reception processing unit 604 within a predetermined time. In the repeated processing, when the traffic volume for the connection terminal device is already stored in the traffic volume storage unit 612, the traffic volume measurement unit 611 adds the newly measured traffic volume to the traffic volume already stored. To do. The traffic amount measurement unit 611 stores the added traffic amount in the traffic amount storage unit 612.

Further, the traffic volume measuring unit 611 receives the identifier of the connected terminal device transmitted from the connected terminal monitoring unit 609. Further, the traffic volume measuring unit 611 receives the transfer data in the frame including the received identifier as the identifier of the frame destination device from the upper layer processing unit 605. The traffic amount measuring unit 611 measures the data amount of the received transfer data as the traffic amount transmitted from the radio base station device 600 to the connection terminal device indicated by the received identifier. The traffic volume measuring unit 611 stores the measured traffic volume in the traffic volume storage unit 612 in association with the received identifier of the connected terminal device. The traffic amount measurement unit 611 repeats the above processing every time it receives transfer data from the upper layer processing unit 605 within a predetermined time. In the repeated processing, when the traffic volume for the connection terminal device is already stored in the traffic volume storage unit 612, the traffic volume measurement unit 611 adds the newly measured traffic volume to the traffic volume already stored. To do. The traffic amount measurement unit 611 stores the added traffic amount in the traffic amount storage unit 612.

Occupancy rate calculation unit 613 calculates the radio space occupancy rate within a predetermined time for each connected terminal device. The calculated radio space occupancy is a ratio in which one or more frames transmitted and received within a predetermined time between the radio base station apparatus 600 and a specific connection terminal apparatus occupy the radio space in terms of time. In the first radio communication system 200 using a predetermined random access method such as CSMA / CA, the radio base station device 600 and the connection terminal device transmit a frame when the shared radio channel is unused. Therefore, each frame transmitted from the radio base station apparatus 600 and the connection terminal apparatus travels in the radio space without overlapping in time. Therefore, the occupancy rate calculation unit 613 performs radio space occupancy of a frame transmitted from the specific connection terminal device to the radio base station device 600 and radio of a frame transmitted from the radio base station device 600 to the specific connection terminal device. Calculate and calculate the space occupancy. The occupation rate calculation unit 613 stores the calculated radio space occupation rate in the occupation rate storage unit 614 for each connection terminal device. FIG. 5 is an example of an occupation rate storage table. Occupancy rate storage unit 614 stores the calculated wireless space occupancy rate for each connected terminal device in the format of occupancy rate storage table 6141 as shown in FIG.

Specifically, the occupation ratio calculation unit 613 receives the identifier of the connection terminal device transmitted from the connection terminal monitoring unit 609. The occupation rate calculation unit 613 calculates the radio space occupation rate of a frame extracted by the radio reception processing unit 603 and including the received identifier as the identifier of the transmission source device. For example, the occupation rate calculation unit 613 measures the processing time of the radio reception processing unit 603 for the frame and calculates a value obtained by dividing the measured processing time by a predetermined time as the radio space occupation rate of the frame. Alternatively, for example, the occupation ratio calculation unit 613 calculates the time length of the frame using information included in the frame extracted by the wireless reception processing unit 603. Then, the occupation rate calculation unit 613 calculates a value obtained by dividing the calculated frame length by a predetermined time as the radio space occupation rate of the frame. The information included in the frame is, for example, information indicating a transmission rate such as Modulation and Coding Scheme (MCS), information indicating a data length of transfer data, and the like. The occupation rate calculation unit 613 stores the calculated radio space occupation rate in the occupation rate storage unit 614 in association with the received identifier of the connected terminal device. Occupancy rate calculation unit 613 repeats the above-described processing every time radio reception processing unit 603 extracts a frame within a predetermined time. In the repeated processing, when the wireless space occupancy for the connection terminal device is already stored in the occupancy storage unit 614, the occupancy calculator 613 has already stored the newly calculated wireless space occupancy. Add to radio space occupancy. The occupation rate calculation unit 613 stores the added radio space occupation rate in the occupation rate storage unit 614.

Also, the occupation rate calculation unit 613 receives the identifier of the connection terminal device transmitted from the connection terminal monitoring unit 609. In addition, the occupation rate calculation unit 613 calculates a radio space occupation rate of a frame that is transmitted by the wireless transmission processing unit 608 and includes the received identifier as the identifier of the destination device. For example, the occupation rate calculation unit 613 measures the processing time of the wireless transmission processing unit 608 for the frame, and calculates a time obtained by dividing the measured processing time by a predetermined time as the wireless space occupation rate of the frame. Alternatively, for example, the occupation rate calculation unit 613 calculates the time length of the frame using information in the frame processed by the wireless transmission processing unit 608 and the number of retransmissions of the frame. Then, the occupation rate calculation unit 613 calculates a time obtained by dividing the calculated frame length by a predetermined time as the radio space occupation rate of the frame. The information included in the frame is, for example, information indicating a transmission rate such as MCS, information indicating the data length of transfer data, and the like. Also, the number of retransmissions of the frame is determined by the radio transmission processing unit 608 until the radio base station apparatus 600 receives a reception confirmation frame indicating that the frame has been normally received from the destination apparatus (radio terminal apparatus 700) of the frame. This is the number of times the frame is retransmitted. The occupation rate calculation unit 613 stores the calculated radio space occupation rate in the occupation rate storage unit 614 in association with the received identifier of the connected terminal device. The occupancy rate calculation unit 613 repeats the above process every time a frame is transmitted by the wireless transmission processing unit 608 within a predetermined time. When the wireless space occupancy rate for the connection terminal device is already stored in the occupancy rate storage unit 614, the occupancy rate calculation unit 613 converts the newly calculated wireless space occupancy rate into the already stored wireless space occupancy rate. to add. The occupation rate calculation unit 613 stores the added radio space occupation rate in the occupation rate storage unit 614.

The load distribution control unit 615 calculates the total traffic amount within a predetermined time by summing the traffic amounts for each connection terminal device stored in the traffic amount storage unit 612. The total traffic amount is a traffic amount generated in the first wireless communication system 200 within a predetermined time. That is, the total traffic volume is the amount of traffic that the radio base station apparatus 600 transmits to each connection terminal apparatus within a predetermined time and the traffic volume that each connection terminal apparatus transmits to the radio base station apparatus 600 within a predetermined time. It is sum. The load distribution control unit 615 determines whether or not the calculated total traffic volume exceeds a traffic volume threshold that is a predetermined value set in advance. The traffic amount threshold is set in advance based on the system capacity of the first radio communication system 200 including the radio base station apparatus 600 and the connection terminal apparatus, for example.

When it is determined that the calculated total traffic volume exceeds the traffic volume threshold, the load distribution control unit 615 identifies a connection terminal apparatus with a high wireless space occupancy rate as a connection terminal apparatus that is a load distribution target. The load distribution target connection terminal apparatus is a radio terminal apparatus 700 that is a target for distributing the load applied to the radio base station apparatus 600 to other radio base station apparatuses 600 in the second radio communication system 400. The load applied to the radio base station apparatus 600 is related to the consumption of radio resources shared by the radio base station apparatus 600 and the radio terminal apparatus 700. For example, if the number of connected terminal apparatuses and the total traffic volume are large, the radio base station The load applied to the device 600 increases.

The load distribution control unit 615 performs control so that the connection between the radio base station apparatus 600 and the connection terminal apparatus targeted for load distribution is disconnected. Also, the load distribution control unit 615 deletes the identifier of the wireless terminal device 700 identified as the connection terminal device targeted for load distribution from the connection terminal storage unit 610.

As a result of the control by the load distribution control unit 615, the wireless terminal device 700 that has been disconnected is attempting to connect to another wireless base station device 600. Therefore, the load applied to the wireless base station device 600 is the other wireless base station device. To 600. Further, the connection between the radio base station apparatus 600 and the connection terminal apparatus to be load-balanced is cut, so that the consumption of radio resources shared by the radio base station apparatus 600 and the connection terminal apparatus decreases. As a result, the throughput of the first wireless communication system 200, which has been reduced with an increase in the consumption of radio resources, is improved and the occurrence of a congestion state is prevented.

The reason why the load distribution control unit 615 identifies a connection terminal device having a high radio space occupancy as a connection terminal device targeted for load distribution will be described below.

The reason why the wireless space occupancy rate for a connection terminal device is high is that the traffic volume related to the connection terminal device is large. As described above, when the amount of traffic is large, the consumption of radio resources used for transmitting traffic also increases. In a situation where the total traffic volume exceeds the traffic volume threshold, a connection terminal apparatus that has a larger traffic volume than other connection terminal apparatuses consumes radio resources to the extent that it interferes with communication of other connection terminal apparatuses. It can be said that it is a terminal device. Therefore, the load distribution control unit 615 identifies a connection terminal device having a high wireless space occupancy rate due to a large traffic volume as a connection terminal device targeted for load distribution.

Also, the reason why the radio space occupancy rate for the connection terminal apparatus is high is that the transmission rate applied to transmission / reception of transfer data between the connection terminal apparatus and the radio base station apparatus 600 is low. The transmission rate applied to the transmission / reception of the transfer data is, for example, the MCS applied to the transfer data according to the intensity of the received power measured by the connecting terminal apparatus with respect to the radio wave (signal) transmitted from the radio base station apparatus 600. It is adaptively controlled by changing. In such a case, a low transmission rate is applied to transmission / reception of transfer data when the strength of the reception power of radio waves is low. When a low transmission rate is applied to transmission / reception of transfer data, the coding rate of information decreases, so the time length for which the frame including the transfer data occupies the radio space becomes relatively long, and the consumption of radio resources also increases. . That is, even when the same transfer data is transmitted / received, if a low transmission rate is applied to the transmission / reception of the transfer data, the use efficiency of the radio resource is lowered. In a situation where the total traffic volume exceeds the traffic volume threshold, it is desirable to improve the usage efficiency of the shared radio resource. However, as described above, the connection terminal device searches for another radio base station device 600 when, for example, the strength of the received power of the radio wave transmitted by the connected radio base station device 600 is less than a predetermined threshold. To do. That is, even if there is another radio base station apparatus 600 that transmits radio waves with higher received power intensity, the received power intensity of radio waves transmitted from the connected radio base station apparatus 600 is less than a predetermined threshold. The connected terminal apparatus does not search for another radio base station apparatus 600 until Therefore, in order to improve the use efficiency of the radio resources, the load distribution control unit 615 determines that the connection terminal device having a high radio space occupancy rate as a load distribution target due to a low transmission rate applied to transmission / reception of transfer data. Identifies as a connected terminal device.

In order to disconnect the connection between the connection terminal device targeted for load distribution and the radio base station device 600, the load distribution control unit 615 performs, for example, the following process. That is, the load distribution control unit 615 instructs the beam control unit 602 to perform beam forming with respect to the antenna 601 so that a null point is formed at a position where the wireless terminal device 700 specified as a load distribution target connection terminal device exists. . The null point is a point where the intensity of received power of a signal (radio wave) transmitted / received between the radio base station apparatus 600 and the radio terminal apparatus 700 becomes less than a predetermined threshold. Note that the position where the load distribution target connection terminal apparatus exists may be represented by the direction or angle where the load distribution target connection terminal apparatus exists based on the position where the radio base station apparatus 600 exists. Further, the null point may be represented by a direction or an angle in which the intensity of the radio wave reception power is less than a predetermined threshold with reference to the position where the radio base station apparatus 600 exists.

In order to disconnect the connection between the connection terminal apparatus targeted for load distribution and the radio base station apparatus 600, the load distribution control unit 615 performs beam transmission so as to form a null point at a position where the connection terminal apparatus targeted for load distribution exists. The reason for instructing the control unit 602 is as follows.

For example, the following method is also conceivable as a method of disconnecting the connection between the connection terminal device targeted for load distribution and the radio base station device 600. That is, radio base station apparatus 600 disconnects the connection with the load distribution target connection terminal apparatus by transmitting an association cancellation signal to the load distribution target connection terminal apparatus. And even if the radio base station apparatus 600 receives the probe request signal broadcast from the disconnected radio terminal apparatus 700, the radio base station apparatus 600 does not transmit the probe response signal to the radio terminal apparatus 700. Disconnected radio terminal apparatus 700 does not receive the probe response signal from radio base station apparatus 600, and therefore does not transmit a connection request signal or a reconnection signal to radio base station apparatus 600. As a result, the disconnected wireless terminal device 700 does not reconnect to the wireless base station device 600. As described above, the radio base station device 600 does not respond to the signal transmitted from the disconnected radio terminal device 700, thereby maintaining the state in which the connection with the load distribution target connection terminal device is disconnected.

However, in the above-described method, a signal transmitted from the disconnected wireless terminal device 700 is received by the wireless base station device 600 as in the above-described probe request signal. That is, the radio resources shared by the radio base station apparatus 600 and the radio terminal apparatus 700 are still consumed by the disconnected radio terminal apparatus 700 even after the connection with the load distribution target connection terminal apparatus is disconnected. Is done. Therefore, radio base station apparatus 600 forms a null point at the position where the connection terminal apparatus targeted for load distribution exists, and sets the position where the connection terminal apparatus targeted for load distribution exists outside the communication area of radio base station apparatus 600. . As a result, radio base station apparatus 600 does not receive the signal transmitted from disconnected radio terminal apparatus 700. Therefore, after the connection with the load distribution target connection terminal device is disconnected, the wireless terminal device 700 that is disconnected is prevented from consuming radio resources.

The beam control unit 602 performs beam forming on the antenna 601 in accordance with the beam forming instruction from the load distribution control unit 615. That is, the beam control unit 602 controls the direction and intensity of the beam formed by the antenna 601 so as to form a null point at the position of the wireless terminal device 700 specified as the load distribution target connection terminal device. The antenna 601 may be an array antenna including a plurality of antenna elements, for example, an adaptive array antenna.

In an adaptive array antenna, the phase and power of signals (radio waves) transmitted and received by each antenna element are controlled by changing the antenna weight of each antenna element. Therefore, the strength of the transmission power for the signal transmitted from the adaptive array antenna can be increased or decreased by changing the antenna weight of each antenna element. Similarly, the strength of the received power with respect to the signal received by the adaptive array antenna can be increased or decreased by changing the antenna weight of each antenna element. The direction in which the wireless terminal device 700 exists with reference to the position where the antenna 601 is present is equal to the arrival direction (Direction Of Arrival) of the signal transmitted by the wireless terminal device 700. Therefore, the direction in which the wireless terminal device 700 exists is determined, for example, from the phase difference of each received signal generated when the signal transmitted from the wireless terminal device 700 is received by each antenna element disposed at a predetermined position. Presumed. The beam control unit 602 changes the antenna weight of each antenna element included in the antenna 601 so that a null point is formed at the position where the connection terminal device targeted for load distribution exists, identified by such estimation.

Further, as a data transmission technique between the radio base station apparatus 600 and the connection terminal apparatus, space division multiplexing (Space Division Multiplexing (SDM)) using Multi-Input Multi-Output (MIMO) may be used. . Such a data transmission technique is standardized in IEEE802.11n, for example. Even in the case where such a data transmission technique is used, the antenna 601 may be an array antenna including a plurality of antenna elements, for example. The beam control unit 602 uses the channel state information (Channel Information (CSI)) for the load distribution target connection terminal device so that the reception power of the radio wave is lowered at the position where the load distribution target connection terminal device exists. The antenna weight of each antenna element included in the antenna 601 is changed. The above-described channel state information is information representing the transmission characteristics of the downlink from the transmission antenna of the radio base station apparatus 600 to the reception antenna of the connection terminal apparatus. For example, the wireless base station device 600 returns the information on the channel state estimated by the connecting terminal device based on the pilot signal transmitted from the wireless base station device 600 to the wireless base station device 600 from the connecting terminal device. Get channel state information.

Note that after a certain period of time elapses after the connection with the connection terminal device that is the load distribution target is disconnected, the load distribution control unit 615 performs beam control so that the beam of the antenna 601 is formed again at the position where the null point is formed. The unit 602 may be instructed.

FIG. 6 is an exemplary hardware configuration diagram of the radio base station apparatus according to the first embodiment. As illustrated in FIG. 6, the radio base station device 800 includes a processor 801, a storage device 802, a radio transmission / reception circuit 803, an antenna 804, a network interface (Network (NIF)) circuit 805, and a bus 806. The processor 801, the storage device 802, the wireless transmission / reception circuit 803, and the network interface circuit 805 are connected to each other via a bus 806. The antenna 804 is connected to the wireless transmission / reception circuit 803.

The processor 801 is a logic circuit or arithmetic circuit that performs arithmetic processing such as Central Processing Unit (CPU) or Digital Signal Processor (DSP). The processor 80 1 corresponds to the frame reception processing unit 604, the upper layer processing unit 605, the frame generation unit 607, the connection terminal monitoring unit 609, the traffic amount measurement unit 611, the occupation rate calculation unit 613, and the load distribution control unit 615.

The storage device 802 is a device in which a processing program executed by the processor 801, data used for processing by the processor 801, and data of a processing result by the processor 801 are stored. The storage device 801 corresponds to the connection terminal storage unit 610, the traffic amount storage unit 612, and the occupation rate storage unit 614.

The wireless transmission / reception circuit 803 is a circuit that processes a wireless signal transmitted / received to / from the wireless terminal device 700 via the antenna 804. The wireless transmission / reception circuit 803 is a circuit that controls the directivity of the antenna 804. The wireless transmission / reception circuit 803 corresponds to the beam control unit 602, the wireless reception processing unit 603, and the wireless transmission processing unit 608.

The antenna 804 radiates the wireless signal processed by the wireless transmission / reception circuit 803 to the wireless space, and receives the wireless signal transmitted from the wireless terminal device 700. The antenna 804 corresponds to the antenna 601.

The network interface circuit 805 is a circuit that processes electrical signals transmitted and received with devices on the wide area network 500 such as the control device 300. The network interface circuit 805 corresponds to the wide area network side interface 606.

As an example of a communication control method according to the first embodiment, load distribution processing executed by the radio base station apparatus 600 will be described. FIG. 7A and FIG. 7B are flowcharts of an exemplary load distribution process executed by the radio base station apparatus according to the first embodiment. Note that a series of load distribution processes as shown in FIGS. 7A and 7B may be repeatedly performed at predetermined time intervals. Further, the processing in each step shown in FIGS. 7A and 7B is not necessarily separated in terms of time, and may be performed in parallel.

When a series of load distribution processing is started (step S1001), the data in the traffic volume storage unit 612 and the occupation rate storage unit 614 are initialized by the load distribution control unit 615. Then, every time the wireless reception processing unit 603 receives a frame having the wireless terminal device 700 as a transmission source device via the antenna 601, the processes in steps S1002 to S1005 are repeated within a predetermined time. Further, every time the upper layer processing unit 605 transmits the transfer data with the wireless terminal device 700 as the destination device to the frame generation unit 607, the processing in steps S1002 to S1005 is repeated within a predetermined time.

First, the processing in steps S1002 to S1005 will be specifically described for a case where the wireless reception processing unit 603 receives a frame having the wireless terminal device 700 as a transmission source device via the antenna 601.

The radio reception processing unit 603 receives a radio signal via the antenna 601 and the beam control unit 602, and extracts a frame from the received radio signal. The wireless reception processing unit 603 transmits the extracted frame to the frame reception processing unit 604.

The frame reception processing unit 604 receives the frame extracted by the wireless reception processing unit 603. The frame reception processing unit 604 extracts the transfer data (packet), the identifier of the frame transmission source device, and the identifier of the frame destination device from the received frame. The frame reception processing unit 604 transmits the extracted transfer data to the upper layer processing unit 605. Also, the frame reception processing unit 604 transmits the extracted identifier of the transmission source device to the connection terminal monitoring unit 609.

The connection terminal monitoring unit 609 receives the identifier of the transmission source device transmitted from the frame reception processing unit 604. The connection terminal monitoring unit 609 checks the received identifier of the transmission source device with the identifier of the connection terminal device stored in the connection terminal storage unit 610. As a result of the collation, when the received identifier of the transmission source device is the identifier of the connection terminal device, the connection terminal monitoring unit 609 acquires the received identifier of the transmission source device as the identifier of the connection terminal device (step S1002). . The connection terminal monitoring unit 609 transmits the received identifier of the transmission source device to the traffic amount measurement unit 611 and the occupation rate calculation unit 613 as the identifier of the connection terminal device.

The occupation rate calculation unit 613 receives the identifier of the connection terminal device transmitted from the connection terminal monitoring unit 609. The occupation rate calculation unit 613 calculates a radio space occupation rate for a frame extracted by the radio reception processing unit 603 and including the received identifier as an identifier of the transmission source device (step S1003). An example of the calculation method of the radio space occupation rate executed by the occupation rate calculation unit 613 has been described above.

The traffic amount measuring unit 611 receives the identifier of the connected terminal device transmitted from the connected terminal monitoring unit 609. Further, the traffic amount measurement unit 611 receives transfer data in a frame including the received identifier as an identifier of the transmission source device from the frame reception processing unit 604. The traffic amount measuring unit 611 measures the data amount of the received transfer data (step S1004). The measured data amount is the traffic amount for the connection terminal device indicated by the received identifier, that is, the traffic amount for the connection terminal device that has transmitted the received transfer data to the radio base station device 600.

In step S1005, the occupation rate calculation unit 613 adds the radio space occupation rate of the frame calculated in step S1003 to the radio space occupation rate corresponding to the identifier of the connected terminal device received in the occupation rate storage unit 614. Are stored in the occupation rate storage unit 614. In addition, the traffic volume measuring unit 611 adds the traffic volume measured in step S1004 to the traffic volume corresponding to the identifier of the connected terminal device received in the traffic volume storage unit 612 and stores it in the occupancy rate storage unit 614. Let

Next, the processing in steps S1002 to S1005 will be specifically described for the case where the upper layer processing unit 605 transmits the transfer data having the wireless terminal device 700 as the destination device to the frame generation unit 607. The case where the upper layer processing unit 605 transmits such transfer data to the frame generation unit 607 occurs, for example, when the radio base station device 600 transfers the transfer data transmitted from the connection terminal device to another connection terminal device. To do. Further, in the case where the upper layer processing unit 605 transmits such transfer data to the frame generation unit 607, for example, the radio base station device 600 transmits the transfer data transmitted from the communication device on the wide area network 500 side to the connection terminal device. Occurs when transferring.

The upper layer processing unit 605 extracts the identifier of the source device of the transfer data and the identifier of the destination device of the transfer data by processing the transfer data. The upper layer processing unit 605 transmits the identifier of the transfer data transmission source device, the identifier of the transfer data destination device, and the transfer data to the frame generation unit 607. In addition, the upper layer processing unit 605 transmits the transfer data to the traffic amount measurement unit 611.

The frame generation unit 607 receives the transfer data, the identifier of the transfer data transmission source device, and the identifier of the transfer data destination device from the upper layer processing unit 605. The frame generation unit 607 generates a frame including the identifier of the frame transmission source device, the identifier of the frame destination device, and the received transfer data. The frame generation unit 607 transmits the generated frame to the wireless transmission processing unit 608. Further, the frame generation unit 607 transmits the identifier of the destination device of the generated frame to the connection terminal monitoring unit 609.

The connection terminal monitoring unit 609 receives the destination device identifier transmitted from the frame generation unit 607. The connection terminal monitoring unit 609 compares the received identifier of the destination device with the identifier of the connection terminal device stored in the connection terminal storage unit 610. As a result of the collation, when the received identifier of the destination device is the identifier of the connecting terminal device, the connecting terminal monitoring unit 609 acquires the received identifier of the destination device as the identifier of the connecting terminal device (step S1002). The connection terminal monitoring unit 609 transmits the received identifier of the transmission source device to the traffic amount measurement unit 611 and the occupation rate calculation unit 613 as the identifier of the connection terminal device.

The occupation rate calculation unit 613 receives the identifier of the connection terminal device transmitted from the connection terminal monitoring unit 609. The occupancy rate calculation unit 613 calculates a radio space occupancy rate for a frame transmitted by the radio transmission processing unit 608 and including the received identifier as the identifier of the destination device (step S1003). An example of the calculation method of the radio space occupation rate executed by the occupation rate calculation unit 613 has been described above.

The traffic amount measuring unit 611 receives the identifier of the connected terminal device transmitted from the connected terminal monitoring unit 609. Further, the traffic volume measurement unit 611 receives the transfer data in the frame generated by the frame generation unit 607 including the received identifier as the identifier of the destination device, from the upper layer processing unit 605. The traffic amount measuring unit 611 measures the data amount of the received transfer data (step S1004). The measured data amount is the amount of traffic transmitted by the radio base station device 600 to the connection terminal device indicated by the received identifier, that is, the amount of traffic for the connection terminal device to which the received transfer data is transmitted.

In step S1005, the occupation rate calculation unit 613 adds the radio space occupation rate of the frame calculated in step S1003 to the radio space occupation rate corresponding to the identifier of the connected terminal device received in the occupation rate storage unit 614. Are stored in the occupation rate storage unit 614. Further, the traffic volume measuring unit 611 adds the traffic volume measured in step S1004 to the traffic volume corresponding to the identifier of the connected terminal device received in the traffic volume storage unit 612 and stores it in the occupation rate storage unit 614. Let

When the processing from step S1002 to step S1005 is performed for a predetermined time, a series of load distribution processing proceeds to step S1006. In step S <b> 1006, the load distribution control unit 615 calculates the total traffic amount within a predetermined time by summing the traffic amounts for each connected terminal device stored in the traffic amount storage unit 612. The load distribution control unit 615 determines whether or not the calculated total traffic amount exceeds a preset traffic amount threshold value (step S1007).

When it is determined that the total traffic volume is equal to or less than the traffic volume threshold (“NO” in step S1007), the load applied to the radio base station apparatus 600 is transferred to the other radio base station apparatuses 600 in the second radio communication system 400. It does not have to be dispersed. Therefore, the series of load distribution processing ends (step S1014).

On the other hand, when it is determined that the total traffic volume exceeds the traffic volume threshold (“YES” in step S1007), the load applied to the radio base station apparatus 600 is set to another radio base station apparatus 600 in the second radio communication system 400. It is desirable to be dispersed. Therefore, the series of load distribution processing proceeds to step S1008.

In step S1008, the load distribution control unit 615 rearranges the identifiers of the connected terminal devices in descending order of radio space occupancy. Specifically, the load distribution control unit 615 rearranges the connection terminal devices indicated by the identifiers stored in the occupation rate storage unit 614 in descending order of corresponding radio space occupation rates. Then, the load distribution control unit 615 performs the loop processing between step S1009 and step S1013 in the order of the corresponding connected terminal devices with the highest radio space occupancy.

Specifically, the load distribution control unit 615 identifies the connection terminal device selected in the loop process as the connection terminal device targeted for load distribution. Then, the load distribution control unit 615 instructs the beam control unit 602 to form a null point at a position where the identified connection terminal device exists (step S1010). The beam control unit 602 performs beam forming with respect to the antenna 601 in accordance with a beam forming instruction from the load distribution control unit 615. That is, the beam control unit 602 controls the direction and intensity of the beam formed by the antenna 601 so as to form a null point at a position where the connection terminal device specified as the load distribution target connection terminal device exists. As a result, the connection between the connection terminal device identified as the load distribution target connection terminal device and the radio base station device 600 is disconnected. The load distribution control unit 615 deletes the identifier of the wireless terminal device 700 identified as the connection terminal device targeted for load distribution from the connection terminal storage unit 610.

The load distribution control unit 615 recalculates the total traffic amount by subtracting the traffic amount for the wireless terminal device 700 specified as the load distribution target connection terminal device from the total traffic amount (step S1011). Then, the load distribution control unit 615 determines whether or not the recalculated total traffic volume is equal to or less than the traffic volume threshold (step S1012).

When it is determined that the total traffic volume is equal to or less than the traffic volume threshold (“YES” in step S1012), the load on the radio base station apparatus 600 is the other radio base station apparatus 600 in the second radio communication system 400. It can be said that it was dispersed. Therefore, the series of load distribution processing ends (step S1014).

On the other hand, when it is determined that the total traffic volume exceeds the traffic volume threshold (“NO” in step S1012), the load applied to the radio base station apparatus 600 is set to another radio base station apparatus 600 in the second radio communication system 400. Further dispersion is desirable. Therefore, the series of load distribution processing is returned to step S1010. That is, the load distribution control unit 615 performs the process in step S1010 for the next connected terminal device in the order of the connected terminal devices having the highest radio space occupancy.

When the loop processing between step S1009 and step S1013 is performed for all the connected terminal devices, the series of load distribution processing ends (step S1014).

Thus, according to the load distribution process according to the first embodiment, the load applied to the radio base station apparatus 600 is distributed to other radio base station apparatuses 600 included in the second radio communication system 400. . Since the load on the radio base station apparatus 600 is distributed, the consumption of radio resources shared by the radio base station apparatus 600 and the radio terminal apparatus 700 is reduced. As a result, the throughput in the first radio communication system 200 sharing the radio resources is improved, and the occurrence of a congestion state in the first radio communication system 200 is prevented.

<Second Embodiment>
The change of the radio base station apparatus 600 to which the radio terminal apparatus 700 is connected may be performed by the first connection method as described above, for example. But the change of the radio base station apparatus 600 to which the radio | wireless terminal apparatus 700 connects may be performed by the 2nd connection method as demonstrated below, for example. That is, the wireless terminal device 700 receives a beacon signal transmitted from each wireless base station device 600 in the second wireless communication system 400 and measures the strength of the received power of the received beacon signal. The wireless terminal device 700 associates the measured value of the received power intensity of each beacon signal with the identifier of each wireless base station device 600 that transmitted the beacon signal, and the wireless base device 700 to which the wireless terminal device 700 is connected Transmit to device 600. The connected radio base station apparatus 600 determines the radio base station apparatus 600 that has transmitted a beacon signal with high received power strength as the radio base station apparatus 600 whose connection is changed from the connected radio base station apparatus 600. . The connected radio base station apparatus 600 notifies the radio terminal apparatus 700 of the determined identifier of the radio base station apparatus 600. The wireless terminal device 700 tries to change the connection from the connected wireless base station device 600 to the wireless base station device 600 indicated by the notified identifier.

The second connection method as described above is standardized in IEEE802.11k and IEEE802.11v, for example. When the wireless terminal device 700 has a function corresponding to the second connection method, the wireless base station device connected to the wireless terminal device 700 may perform load distribution processing according to the second embodiment described below. Good.

FIG. 8 is an exemplary functional configuration diagram of the radio base station apparatus according to the second embodiment. In FIG. 8, among the constituent elements of the radio base station apparatus 900 according to the second embodiment, the same constituent elements as those of the radio base station apparatus 600 (see FIG. 2) include the constituent elements of the radio base station apparatus 600. The same reference numerals as those of the reference numerals are attached. The radio base station apparatus 900 may be included in the second radio communication system 400 (see FIG. 1) instead of the radio base station apparatus 600. Alternatively, the radio base station apparatus 900 may be included in the second radio communication system 400 together with the radio base station apparatus 600.

Each wireless terminal device 700 connected to the wireless base station device 900, that is, the connected terminal device receives a beacon signal transmitted from each wireless base station device in the second wireless communication system 400, and receives the received beacon signal. Measure the received power intensity. As described above, each radio base station device in the second radio communication system 400 may be the radio base station device 600 or the radio base station device 900. Further, the measurement by each connection terminal apparatus may be repeatedly performed during connection with the radio base station apparatus 900. Each connection terminal device transmits the measured value of the received power intensity of each beacon signal to the connected radio base station device 900 in association with the identifier of each radio base station device that transmitted the beacon signal.

The radio base station apparatus 900 receives the value of the received power intensity of each beacon signal and the identifier of each radio base station apparatus corresponding to the value from each connection terminal apparatus. Based on the received information, the radio base station apparatus 900 acquires, for each connected terminal apparatus, information on other radio base station apparatuses that can be connected to the connected terminal apparatus in addition to the currently connected radio base station apparatus 900. . A beacon signal whose received power intensity measured by the connected terminal device is greater than or equal to a predetermined threshold is transmitted from other beacon signals received by the connected terminal device to other wireless base station devices to which the connected terminal device can be connected. Wireless base station apparatus. Other radio base station apparatuses to which the connection terminal apparatus can be connected besides the currently connected radio base station apparatus 900 exist, for example, adjacent to the radio base station apparatus 900 to which the connection terminal apparatus is connected. Therefore, in the following description, “another radio base station apparatus to which a connection terminal apparatus can be connected other than the currently connected radio base station apparatus 900” is referred to as an adjacent base station apparatus for convenience. The adjacent base station apparatus is a radio base station apparatus included in the second radio communication system 400, and may be the radio base station apparatus 900 or the radio base station apparatus 600.

The radio base station apparatus 900 determines whether or not the total traffic volume obtained by totaling the traffic volume for each connection terminal apparatus exceeds a predetermined traffic volume threshold set in advance. When it is determined that the total traffic volume exceeds the traffic volume threshold, the radio base station apparatus 900 first identifies a connection terminal apparatus to be load-balanced from among the connection terminal apparatuses having adjacent base station apparatuses. Then, the radio base station apparatus 900 disconnects the connection with the identified connection terminal apparatus. Further, if the total traffic volume exceeds the traffic volume threshold even when the connection with the connection terminal apparatus having the adjacent base station apparatus is disconnected, the radio base station apparatus 900 is the middle of the connection terminal apparatus that does not have the adjacent base station apparatus. Next, the connection terminal device for load distribution is identified. Then, the radio base station apparatus 900 disconnects the connection with the identified connection terminal apparatus.

The load applied to the radio base station apparatus 900 is distributed to other radio base station apparatuses included in the second radio communication system 400 by the load distribution process performed by the radio base station apparatus 900 according to the second embodiment. By distributing the load on the radio base station apparatus 900, the consumption of radio resources shared by the radio base station apparatus 900 and the radio terminal apparatus 700 is reduced. As a result, the throughput in the first radio communication system 200 sharing the radio resources is improved, and the occurrence of a congestion state in the first radio communication system 200 is prevented.

Further, in the load distribution process by the radio base station apparatus 900 according to the second embodiment, a connection terminal apparatus having an adjacent base station apparatus is first selected as a connection terminal apparatus for load distribution. Therefore, according to the load distribution process according to the second embodiment, the certainty that the disconnected wireless terminal device 700 is connected to another wireless base station device in the second wireless communication system 400 is further increased. The load distribution in the second wireless communication system 400 is more reliably performed.

As shown in FIG. 8, the radio base station apparatus 900 includes a frame reception processing unit 901 instead of the frame reception processing unit 604 (see FIG. 2). Radio base station apparatus 900 further includes an adjacent base station monitoring unit 902 and an adjacent base station storage unit 903 as an example of a monitoring unit. The radio base station apparatus 900 further includes a load distribution control unit 904 as an example of a first control unit instead of the load distribution control unit 615 (see FIG. 2).

The frame reception processing unit 901 has the same function as the above-described frame reception processing unit 604 (see FIG. 2). Further, the frame reception processing unit 901 further has a function of transmitting transfer data extracted from the received frame to the adjacent base station monitoring unit 902.

The adjacent base station monitoring unit 902 receives the transfer data transmitted from the frame reception processing unit 901. The adjacent base station monitoring unit 902 extracts the identifier of the connected terminal device, the value of the received power intensity of each beacon signal, and the identifier of each radio base station device that transmitted the beacon signal from the received transfer data. In the adjacent base station monitoring unit 902, the extracted identifier indicates a radio base station apparatus that has transmitted a beacon signal having a value exceeding a predetermined threshold among the values of the received power intensity of each extracted beacon signal. It is specified as an adjacent base station device of the connection terminal device. As a result of such processing, there may be a connection terminal device for which an adjacent base station device is not specified. In addition, there may be a connection terminal device in which a plurality of adjacent base station devices are specified. The adjacent base station monitoring unit 902 stores the identified identifier of the adjacent base station device in the adjacent base station storage unit 903 in association with the extracted identifier of the connected terminal device. Through the above-described processing by the adjacent base station monitoring unit 902, the adjacent base station storage unit 903 stores the identifier of the adjacent base station device for each connected terminal device. FIG. 9 is an example of an adjacent base station storage table. The adjacent base station storage unit 903 stores the identifier of the adjacent base station device for each connected terminal device in the format of the adjacent base station storage table 9031 as shown in FIG. In the example illustrated in FIG. 9, the connection terminal apparatus with the identifier “11: 22: 33: 44: 55: 66” has an adjacent base station apparatus with the identifier “12: 34: 56: 78: 90: 12”. To do. There is no adjacent base station device in the connection terminal device with the identifier “77: 88: 99: 00: AA: BB”. The connecting terminal device with the identifier “AA: BB: CC: DD: EE: FF” includes the adjacent base station device with the identifier “01: 23: 45: 67: 89: 01” and the identifier “AB: CD: EF: GH”. : IJ: KL ”and an adjacent base station device.

The load distribution control unit 904 calculates the total traffic amount within a predetermined time by summing the traffic amounts for each connection terminal device stored in the traffic amount storage unit 612. The load distribution control unit 904 determines whether the calculated total traffic volume exceeds a preset traffic volume threshold.

When it is determined that the calculated total traffic volume exceeds the traffic volume threshold value, the load distribution control unit 904 identifies a connection terminal apparatus having a high radio space occupancy rate and having an adjacent base station apparatus as a connection terminal apparatus targeted for load distribution. To do. That is, the load distribution control unit 904 specifies a connection terminal device having a high radio space occupancy stored in the occupancy storage unit 614 and storing the identifier of the adjacent base station device in the adjacent base station storage unit 903. The load distribution control unit 904 instructs the beam control unit 602 to perform beam forming for the antenna 601 so that a null point is formed at a position where the identified connection terminal device exists. By forming a null point by beam forming by the beam control unit 602, the connection between the radio base station device 900 and the connection terminal device to be load-balanced is disconnected. The load distribution control unit 904 deletes the identifier of the wireless terminal device 700 specified as the connection terminal device targeted for load distribution from the connection terminal storage unit 610.

In addition, when it is determined that the total traffic volume exceeds the traffic volume threshold even after all the connection terminal apparatuses having the adjacent base station apparatuses are disconnected, the load distribution control unit 904 determines the remaining connection terminal apparatuses Perform load balancing processing for. That is, the load distribution control unit 904 loads a connection terminal device having a high radio space occupation rate stored in the occupation rate storage unit 614 and does not store the identifier of the adjacent base station device in the adjacent base station storage unit 903 as a load distribution target. Specified as a connected terminal device. The load distribution control unit 904 instructs the beam control unit 602 to perform beam forming for the antenna 601 so that a null point is formed at a position where the specified wireless terminal device 700 exists. By forming a null point by beam forming by the beam control unit 602, the connection between the radio base station device 900 and the connection terminal device to be load-balanced is disconnected. The load distribution control unit 904 deletes the identifier of the wireless terminal device 700 specified as the connection terminal device targeted for load distribution from the connection terminal storage unit 610.

Note that after a certain period of time has elapsed after the connection with the connection terminal device that is the load distribution target is disconnected, the load distribution control unit 904 performs beam control so that the beam of the antenna 601 is formed again at the position where the null point is formed. The unit 602 may be instructed.

The radio base station apparatus 900 may be configured by the hardware shown in FIG. For example, the processor 801 corresponds to the frame reception processing unit 901, the adjacent base station monitoring unit 902, and the load distribution control unit 904 in addition to the components included in the radio base station apparatus 600 in the same manner. The storage device 802 corresponds to the adjacent base station storage unit 903 in addition to the components included in the radio base station device 600 in the same manner.

As an example of a communication control method according to the second embodiment, load distribution processing executed by the radio base station apparatus 900 will be described. 10A to 10C are flowcharts of an exemplary load distribution process executed by the radio base station apparatus according to the second embodiment. Note that a series of load distribution processes as shown in FIGS. 10A to 10C may be repeatedly executed at predetermined time intervals. Also, the processing in each step shown in FIGS. 10A to 10C is not necessarily separated in terms of time, and may be performed in parallel.

When a series of load distribution processing is started (step S2001), data in the traffic volume storage unit 612 and the occupation rate storage unit 614 is initialized by the load distribution control unit 904. When the adjacent base station monitoring unit 902 receives transfer data including information related to the adjacent base station device of the connected terminal device from the frame reception processing unit 901, the process in step S2002 is performed.

That is, in step S2002, the adjacent base station monitoring unit 902 receives the transfer data transmitted from the frame reception processing unit 901. The adjacent base station monitoring unit 902 extracts the identifier of the connected terminal device, the value of the received power intensity of each beacon signal, and the identifier of each radio base station device that transmitted the beacon signal from the received transfer data. The adjacent base station monitoring unit 902 connects the wireless base station apparatus that has transmitted a beacon signal having a value exceeding a predetermined threshold among the extracted intensity values of each received beacon signal by the extracted identifier. It is specified as an adjacent base station device of the terminal device. The adjacent base station monitoring unit 902 stores the identified identifier of the adjacent base station device in the adjacent base station storage unit 903 in association with the extracted identifier of the connected terminal device.

The processing in steps S2003 to S2006 is repeated within a predetermined time every time the wireless reception processing unit 603 receives a frame having the wireless terminal device 700 as a transmission source device via the antenna 601. Further, the processes in steps S2003 to S2006 are repeated within a predetermined time every time the upper layer processing unit 605 transmits the transfer data having the wireless terminal device 700 as the destination device to the frame generation unit 607. The processing in steps S2003 to S2006 may be the same as the processing in steps S1002 to S1005 described above with reference to FIGS. 7A and 7B.

When the processing from step S2003 to step S2006 is performed for a predetermined time, a series of load distribution processing proceeds to step S2007. In step S2007, the load distribution control unit 904 calculates the total traffic amount within a predetermined time by summing the traffic amounts for each connection terminal device stored in the traffic amount storage unit 612. The load distribution control unit 904 determines whether or not the calculated total traffic amount exceeds a preset traffic amount threshold value (step S2008).

When it is determined that the total traffic volume is equal to or less than the traffic volume threshold (“NO” in step S2008), the load on the radio base station apparatus 900 is distributed to other radio base station apparatuses in the second radio communication system 400. It does not have to be done. Therefore, the series of load distribution processing ends (step S2024).

On the other hand, when it is determined that the total traffic volume exceeds the traffic volume threshold (“YES” in step S2008), the load applied to the radio base station apparatus 900 is transferred to other radio base station apparatuses in the second radio communication system 400. It is desirable to disperse. Therefore, the series of load distribution processing proceeds to step S2009.

In step S2009, the load distribution control unit 904 rearranges the identifiers of the connected terminal devices stored in the occupation rate storage unit 614 in descending order of the corresponding radio space occupation rate. Then, the load distribution control unit 904 performs the first loop processing between step S2010 and step S2017 in the order of the corresponding connected terminal devices with the highest radio space occupancy.

Specifically, the load distribution control unit 904 determines whether or not there is an adjacent base station device in the connection terminal device selected in the first loop processing by referring to the adjacent base station storage unit 903 ( Step S2011).

When it is determined that there is no adjacent base station device in the connection terminal device selected in the first loop process (“NO” in step S2011), the load distribution control unit 904 is selected in the first loop process. The identifier of the connected terminal device is held (step S2012). Also, the load distribution control unit 904 increments the count number for the connected terminal device that does not have an adjacent base station device (step S2013). Then, the series of load distribution processing is returned to step S2011. That is, the load distribution control unit 904 performs the process in step S2011 on the next connection terminal device in the order of the connection terminal devices having the highest radio space occupancy.

On the other hand, when it is determined that there is an adjacent base station device in the connection terminal device selected in the first loop process (“YES” in step S2011), the load distribution control unit 904 performs load distribution on the connection terminal device. Identifies the target connection terminal device. Then, the load distribution control unit 904 instructs the beam control unit 602 to form a null point at the position of the identified connection terminal device (step S2014). The beam control unit 602 controls the direction and intensity of the beam formed by the antenna 601 so that a null point is formed at a position where the connection terminal device specified as the load distribution target connection terminal device exists. As a result, the connection between the identified connection terminal device and the radio base station device 900 is disconnected. The load distribution control unit 904 deletes the identifier of the wireless terminal device 700 specified as the connection terminal device targeted for load distribution from the connection terminal storage unit 610.

The load distribution control unit 904 recalculates the total traffic amount by subtracting the traffic amount for the wireless terminal device 700 specified as the load distribution target connection terminal device from the total traffic amount (step S2015). Then, the load distribution control unit 904 determines whether or not the recalculated total traffic amount is equal to or less than the traffic amount threshold (step S2016).

When it is determined that the total traffic volume is equal to or less than the traffic volume threshold (“YES” in step S2016), the load applied to the radio base station apparatus 900 is transferred to other radio base station apparatuses in the second radio communication system 400. It can be said that it was distributed. Therefore, the series of load distribution processing ends (step S2024).

On the other hand, when it is determined that the total traffic volume exceeds the traffic volume threshold (“NO” in step S2016), the load applied to the radio base station apparatus 900 is transferred to other radio base station apparatuses in the second radio communication system 400. It is desirable to further disperse. Therefore, the first loop process is returned to step S2011. That is, the load distribution control unit 904 performs the process in step S2011 on the next connection terminal device in the order of the connection terminal devices having the highest radio space occupancy.

When the first loop processing is performed for all the connected terminal devices, the series of load distribution processing proceeds to step S2018. In step S2018, the load distribution control unit 904 has the corresponding wireless space occupancy stored in the occupancy storage unit 614 for the identifier held in step S2012, that is, the identifier of the connected terminal device that does not have an adjacent base station device. Sort in order. Then, the load distribution control unit 904 performs the second loop processing between step S2019 and step S2023 in the order of the connection terminal devices having the corresponding higher radio space occupancy ratio among the connection terminal devices without the adjacent base station devices. .

Specifically, the load distribution control unit 904 identifies the connection terminal device selected in the second loop process as the connection terminal device targeted for load distribution. Then, the load distribution control unit 904 instructs the beam control unit 602 to form a null point at a position where the identified connection terminal device exists (step S2020). The beam control unit 602 controls the direction and intensity of the beam formed by the antenna 601 so that a null point is formed at a position where the connection terminal device specified as the load distribution target connection terminal device exists. As a result, the connection between the identified connection terminal device and the radio base station device 900 is disconnected. The load distribution control unit 904 deletes the identifier of the wireless terminal device 700 specified as the connection terminal device targeted for load distribution from the connection terminal storage unit 610.

The load distribution control unit 904 recalculates the total traffic amount by subtracting the traffic amount for the wireless terminal device 700 selected as the load distribution target connection terminal device from the total traffic amount (step S2021). Then, the load distribution control unit 904 determines whether or not the recalculated total traffic amount is equal to or less than the traffic amount threshold (step S2022).

When it is determined that the total traffic amount is equal to or less than the traffic amount threshold (“YES” in step S2022), the load applied to the radio base station device 900 is transferred to other radio base station devices in the second radio communication system 400. It can be said that it was distributed. Therefore, the series of load distribution processing ends (step S2024).

On the other hand, when it is determined that the total traffic volume exceeds the traffic volume threshold (“NO” in step S2022), the load applied to the radio base station apparatus 900 is transferred to other radio base station apparatuses in the second radio communication system 400. It is desirable to further disperse. Therefore, the second loop process is returned to step S2020. That is, the load distribution control unit 904 performs the process in step S2022 for the next connected terminal device in the order of the connected terminal devices with the highest radio space occupancy.

When the second loop processing is performed for all the connected terminal devices that do not have the adjacent base station device, the series of load distribution processing ends (step S2024).

As described above, according to the load distribution processing according to the second embodiment, the load applied to the radio base station apparatus 900 is distributed to other radio base station apparatuses included in the second radio communication system 400. By distributing the load on the radio base station apparatus 900, the consumption of radio resources shared by the radio base station apparatus 900 and the radio terminal apparatus 700 is reduced. As a result, the throughput in the first radio communication system 200 sharing the radio resources is improved, and the occurrence of a congestion state in the first radio communication system 200 is prevented.

Also, in the load distribution process according to the second embodiment, a connection terminal device having an adjacent base station device is first selected as a connection terminal device for load distribution. Therefore, according to the load distribution process according to the second embodiment, the certainty that the disconnected wireless terminal device 700 is connected to another wireless base station device in the second wireless communication system 400 increases. Load distribution within the second wireless communication system 400 is more reliably performed.

<Third Embodiment>
As described above, in the first and second embodiments, the radio base station apparatus 600 or 900 executes load distribution processing in the second radio communication system 400. As a result, the throughput in the first radio communication system 200 is improved, and the occurrence of a congestion state in the first radio communication system 200 is prevented.

On the other hand, in the third embodiment, the control device executes load distribution processing in the second wireless communication system 400. As a result, the throughput in the first radio communication system 200 is improved, and the occurrence of a congestion state in the first radio communication system 200 is prevented.

In the third embodiment, the control device and the radio base station device managed by the control device in order to execute load distribution processing in the second radio communication system 400 will be described below, for example. It is configured to perform processing.

FIG. 11 is an exemplary functional configuration diagram of the radio base station apparatus according to the third embodiment. FIG. 13 is an exemplary functional configuration diagram of the control device according to the third embodiment. A radio base station apparatus 1000 illustrated in FIG. 11 is included in each first radio communication system 200 in the second radio communication system 400 (see FIG. 1) instead of the radio base station apparatus 600 or 900. 13 is included in the second radio communication system 400 (see FIG. 1) in place of the control apparatus 300, and is connected to each radio base station apparatus 1000.

Similarly to the radio base station apparatuses 600 and 900, the radio base station apparatus 1000 calculates the radio space occupancy rate of the frame received via the antenna 601. The radio base station apparatus 1000 transmits the calculated radio space occupancy and the identifier of the connection terminal apparatus that is the frame transmission source apparatus to the control apparatus 1100. Similarly to radio base station apparatuses 600 and 900, radio base station apparatus 1000 transmits transfer data in the received frame to control apparatus 1100.

Similarly to the radio base station apparatuses 600 and 900, the radio base station apparatus 1000 receives and receives the transfer data destined for the radio terminal apparatus 700 from the control apparatus 1100 via the wide area network side interface 606. A frame including the transferred data is generated. Then, similarly to the radio base station apparatuses 600 and 900, the radio base station apparatus 1000 calculates the radio space occupancy rate of the generated frame. The radio base station apparatus 1000 transmits the calculated radio space occupancy rate to the control apparatus 1100 together with the identifier of the connection terminal apparatus that is the frame destination apparatus.

Further, the radio base station apparatus 1000 is a radio terminal apparatus that can be connected to the radio base station apparatus 1000 among the radio terminal apparatuses 700 that are connected to other radio base station apparatuses 1000 in the second radio communication system 400. 700 is monitored. A wireless terminal device 700 connected to another wireless base station device 1000 exists in the communication area of the other wireless base station device 1000. Therefore, in the following description, “wireless terminal apparatus 700 connected to another radio base station apparatus 1000” is referred to as another area terminal apparatus for convenience.

Specifically, the radio base station apparatus 1000 receives a radio signal (radio wave) transmitted from another area terminal apparatus, and measures the strength of the received power of the received radio signal. When the measured intensity value of the received power is equal to or greater than a predetermined threshold, the radio base station apparatus 1000 identifies the other area terminal apparatus as the radio terminal apparatus 700 that can be connected to the radio base station apparatus 1000. The radio base station apparatus 1000 stores the identifier of the identified other area terminal apparatus. The radio base station apparatus 1000 repeats the above processing every time it receives a radio signal transmitted from another area terminal apparatus. Then, after elapse of a predetermined storage time, radio base station apparatus 1000 transmits the stored identifiers of all other area terminal apparatuses to control apparatus 1100.

On the other hand, the control device 1100 receives the radio space occupancy rate and the identifier of the connection terminal device for which the radio space occupancy rate has been calculated from each radio base station device 1000 in the second radio communication system 400. The control apparatus 1100 stores the received radio space occupancy in association with the received identifier of the connected terminal apparatus for each radio base station apparatus 1000 that has transmitted each received information.

Also, the control device 1100 measures the traffic volume of transfer data transmitted from the radio base station device 1000 to the connection terminal device. For each radio base station apparatus 1000 that transmits transfer data, the control apparatus 1100 stores the measured traffic volume in association with the identifier of the connection terminal apparatus that is the transfer data destination apparatus. The control apparatus 1100 transmits the transfer data to the radio base station apparatus 1000.

Further, the control device 1100 receives the transfer data transmitted from the connection terminal device to the radio base station device 1000 from the radio base station device 1000. The control device 1100 measures the traffic volume of the received transfer data. For each radio base station apparatus 1000 to which the transfer data is transmitted, the control apparatus 1100 stores the measured traffic volume in association with the identifier of the connection terminal apparatus that is the transmission data transmission source apparatus.

Also, the control device 1100 receives the identifier of the other area terminal device from each radio base station device 1000 in the second radio communication system 400. The control apparatus 1100 stores the identifier of the radio base station apparatus 1000 that has transmitted the identifier of the other area terminal apparatus for each received identifier of the other area terminal apparatus. With such storage, the control device 1100 identifies the adjacent base station device for each connection terminal device. In the third embodiment, the adjacent base station apparatus refers to another radio base station apparatus 1000 to which a connection terminal apparatus can be connected other than the currently connected radio base station apparatus 1000.

The control device 1100 uses the traffic volume, the radio space occupancy rate, and information related to the adjacent base station device of each connection terminal device to determine the connection terminal device to be load-balanced for the radio base station device 1000 where load distribution is desired. Identify. For example, the control apparatus 1100 gives priority to a connection terminal apparatus having an adjacent base station apparatus capable of accommodating the traffic amount for the connection terminal apparatus as a connection terminal apparatus to be load-balanced among the connection terminal apparatuses having a high radio space occupation ratio. To be specific. The control apparatus 1100 transmits an instruction to distribute the load caused by the identified connection terminal apparatus to other radio base station apparatuses 1000 to the radio base station apparatus 1000 connected to the identified connection terminal apparatus.

The radio base station apparatus 1000 disconnects the connection with the load distribution target connection terminal apparatus in accordance with the load distribution instruction received from the control apparatus 1100. Specifically, the radio base station apparatus 1000 forms a null point at a position where the connection terminal apparatus targeted for load distribution exists.

The null point is formed at the position where the connection terminal device targeted for load distribution exists, so that the position where the connection terminal device targeted for load distribution exists is outside the communication area of the radio base station apparatus 1000. As a result, the connection between the radio base station apparatus 1000 and the load distribution target connection terminal apparatus is disconnected. Since the disconnected radio terminal device 700 tries to connect to another radio base station device 1000, the load caused by the load distribution target connection terminal device is distributed to the other radio base station device 1000. Further, the connection between the radio base station apparatus 1000 and the load distribution target connection terminal apparatus is disconnected, so that the consumption of radio resources shared by the radio base station apparatus 1000 and the connection terminal apparatus decreases. As a result, the throughput in the first wireless communication system 200, which has been reduced with an increase in the consumption of wireless resources, is improved and the occurrence of a congestion state is prevented.

Also, the radio base station apparatus 1000 does not receive a radio signal transmitted from the radio terminal apparatus 700 that has been disconnected by the load distribution process. Therefore, after the connection with the connection terminal device targeted for load distribution is disconnected, the wireless terminal device 700 that has been disconnected consumes radio resources shared by the wireless base station device 1000 and the connection terminal device. Is prevented.

In FIG. 11, the same constituent elements as those of the radio base station apparatuses 600 (see FIG. 2) and 900 (see FIG. 8) among the constituent elements of the radio base station apparatus 1000 include the constituent elements of the radio base station apparatuses 600 and 900. The same reference numerals as those in FIG.

Compared with the radio base station apparatus 600 (see FIG. 2), the radio base station apparatus 1000 includes a frame reception processing unit 1001 instead of the frame reception processing unit 604. The radio base station apparatus 1000 further includes a connection terminal monitoring unit 1002 in place of the connection terminal monitoring unit 609. Radio base station apparatus 1000 further includes another area terminal monitoring unit 1003 and another area terminal storage unit 1004. Radio base station apparatus 1000 further includes an occupancy rate calculation unit 1005 instead of occupancy rate calculation unit 613. The radio base station apparatus 1000 further includes an upper layer processing unit 1006 in place of the upper layer processing unit 605. Radio base station apparatus 1000 further includes a load distribution instruction reading unit 1007 in place of load distribution control unit 615. Further, compared to the radio base station apparatus 600 (see FIG. 2), the radio base station apparatus 1000 may not include the traffic amount measurement unit 611, the traffic amount storage unit 612, and the occupation rate storage unit 614.

The frame reception processing unit 1001 has the same function as the frame reception processing unit 604 (see FIG. 2). The frame reception processing unit 1001 further has a function of performing processing as described below.

Among the frames received by the frame reception processing unit 1001 from the wireless reception processing unit 603, there is a frame whose frame destination device is not the wireless base station device 1000. When the identifier of the other radio base station apparatus 1000 is extracted as the identifier of the frame destination device, the frame reception processing unit 1001 uses the identifier of the frame transmission source device, that is, the identifier of the other area terminal device, as the other area terminal monitoring unit. 1003.

The connected terminal monitoring unit 1002 has the same function as the connected terminal monitoring unit 609 (see FIGS. 2 and 8), and monitors the wireless terminal device 700 connected to the wireless base station device 1000, that is, the connected terminal device. The connected terminal monitoring unit 1002 further has a function of performing processing as described below.

The connected terminal monitoring unit 1002 transmits the identifier of the wireless terminal device 700 with which the connection with the wireless base station device 1000 has been established to the upper layer processing unit 1006 together with a flag indicating connection establishment. Also, the connected terminal monitoring unit 1002 transmits the identifier of the wireless terminal device 700 that has been disconnected from the wireless base station device 1000 to the upper layer processing unit 1006 together with a flag indicating the disconnected connection.

The other area terminal monitoring unit 1003 monitors the radio terminal apparatus 700 that can be connected to the radio base station apparatus 1000 among the other area terminal apparatuses. Specifically, the other area terminal monitoring unit 1003 receives the identifier of the other area terminal device from the frame reception processing unit 1001. The other area terminal monitoring unit 1003 measures the strength of the received power of the radio signal transmitted from the other area terminal device indicated by the received identifier and received by the radio reception processing unit 603. The other area terminal monitoring unit 1003 compares the measured received power intensity value with a predetermined threshold value. When the measured received power intensity value is equal to or greater than a predetermined threshold, the other area terminal monitoring unit 1003 can connect the other area terminal apparatus indicated by the received identifier to the radio base station apparatus 1000. As specified. The other area terminal monitoring unit 1003 stores the identified identifier of the other area terminal device in the other area terminal storage unit 1004. FIG. 12 is an example of another area terminal storage table. The other area terminal storage unit 1004 stores the identifier of the other area terminal device identified as the wireless terminal device 700 that can be connected to the wireless base station device 1000 in the format of the connected terminal storage table 10041 as shown in FIG. After the elapse of a predetermined storage time, the other area terminal monitoring unit 1003 transmits the identifiers of all other area terminal devices stored in the other area terminal storage unit 1004 to the higher layer processing unit 1006.

The occupancy rate calculation unit 1005 calculates the radio space occupancy rate for the connected terminal device, similarly to the occupancy rate calculation unit 613 (see FIGS. 2 and 8). Also, the occupancy rate calculation unit 1005 transmits the calculated radio space occupancy rate and the identifier of the connected terminal device for which the radio space occupancy rate has been calculated to the upper layer processing unit 1006.

The upper layer processing unit 1006 has the same function as the upper layer processing unit 605 (see FIGS. 2 and 8). The upper layer processing unit 1006 further has a function of performing processing as described below.

The upper layer processing unit 1006 receives from the connection terminal monitoring unit 1002 the identifier of the connection terminal device and a flag indicating connection establishment or connection disconnection. The upper layer processing unit 1006 includes transfer data (packet) including the received identifier of the connection terminal apparatus, the identifier of the radio base station apparatus 1000 connected to the connection terminal apparatus, and a flag indicating connection establishment or connection disconnection. Is generated. The upper layer processing unit 1006 transmits the generated transfer data to the wide area network side interface 606.

Further, the upper layer processing unit 1006 receives the identifier of the other area terminal device stored in the other area terminal storage unit 1004 from the other area terminal device monitoring unit 1003. Upper layer processing section 1006 generates transfer data including an identifier of another area terminal device and an identifier of radio base station apparatus 1000 that identifies the other area terminal device. The upper layer processing unit 1006 transmits the generated transfer data to the wide area network side interface 606.

Further, the upper layer processing unit 1006 receives from the occupation rate calculation unit 1005 the radio space occupancy rate of the frame and the identifier of the connected terminal device for which the radio space occupancy rate has been calculated. The upper layer processing unit 1006 generates transfer data including the radio space occupancy rate, the identifier of the connection terminal device from which the radio space occupancy rate has been calculated, and the identifier of the radio base station device 1000 from which the radio space occupancy rate has been calculated. To do. The upper layer processing unit 1006 transmits the generated transfer data to the wide area network side interface 606.

The wide area network side interface 606 includes the transfer data received from the higher layer processing unit 1006 and generates a frame having the control device 1100 as the destination device. The wide area network side interface 606 transmits an electrical signal including the generated frame to the control device 1100.

Further, the wide area network side interface 606 receives the electrical signal transmitted from the control device 1100 and extracts the frame by processing the received electrical signal. The wide area network side interface 606 extracts the transfer data (packet), the identifier of the frame transmission source device, and the identifier of the frame destination device from the extracted frame. The wide area network side interface 606 transmits the extracted transfer data to the upper layer processing unit 1006.

The upper layer processing unit 1006 receives the transfer data extracted by the wide area network side interface 606 and processes the received transfer data. Depending on the transfer data processed by the upper layer processing unit 1006, a load distribution instruction of the control device 1100 is included. When the processed transfer data includes the load distribution instruction of the control device 1100, the upper layer processing unit 1006 transmits the load distribution instruction to the load distribution instruction reading unit 1007.

The load distribution instruction reading unit 1007 receives the load distribution instruction transmitted from the higher layer processing unit 1006. The load distribution instruction reading unit 1007 reads the identifier of the connection terminal device targeted for load distribution instructed by the control apparatus 1100 from the received load distribution instruction. The load distribution instruction reading unit 1007 instructs the beam control unit 602 to disconnect the connection between the connection terminal device targeted for load distribution and the radio base station device 1000 according to the read identifier. Specifically, the load distribution instruction reading unit 1007 instructs the beam control unit 602 to perform beam forming in which a null point is formed at a position where the connection terminal device indicated by the read identifier exists.

The beam control unit 602 controls the direction and intensity of the beam formed by the antenna 601 so as to form a null point at the position where the connection terminal device targeted for load distribution exists in accordance with the beam forming instruction from the load distribution instruction reading unit 1007. To do. The load distribution instruction reading unit 1007 deletes the identifier of the wireless terminal device 700 identified as the load distribution target connection terminal device from the connection terminal storage unit 610.

The radio base station apparatus 1000 may be configured by the hardware shown in FIG. For example, the processor 801 includes the frame reception processing unit 1001, the connected terminal monitoring unit 1002, the other area terminal monitoring unit 1003, and the occupation rate calculation unit 1005 in addition to the components included in the radio base station apparatus 600 in the same manner. Correspond. The processor 801 also corresponds to the upper layer processing unit 1006 and the load distribution instruction reading unit 1007. The storage device 802 corresponds to the other area terminal storage unit 1004 in addition to the components similarly included in the radio base station device 600.

As shown in FIG. 13, the control device 1100 includes a radio base station side interface 1101, a frame reception processing unit 1102, an upper layer processing unit 1103, a wide area network side interface 1104, and a frame generation unit 1105. The control apparatus 1100 further includes a connection terminal monitoring unit 1106, a connection terminal storage unit 1107, an adjacent base station monitoring unit 1108, and an adjacent base station storage unit 1109. The control device 1100 further includes an occupation rate reading unit 1110, an occupation rate storage unit 1111, a traffic amount measurement unit 1112, a traffic amount storage unit 1113, and a load distribution control unit 1114.

The radio base station side interface 1101 is a communication interface for the control device 1100 to receive an electric signal transmitted from the radio base station device 1000 and for the control device 1100 to transmit an electric signal to the radio base station device 1000. For example, the radio base station side interface 1101 extracts a frame from the electrical signal transmitted from the radio base station apparatus 1000 and transmits the extracted frame to the frame reception processing unit 1102.

The frame reception processing unit 1102 receives the frame extracted by the radio base station side interface 1101. The frame reception processing unit 1102 extracts various data included in the frame by processing the received frame. The various data extracted by the frame reception processing unit 1102 includes transfer data (packets), which is a data body included in the frame, an identifier of the frame transmission source device, and an identifier of the frame destination device. Each identifier of the transmission source device and the destination device is, for example, a MAC address. The frame transmission source apparatus is, for example, the radio base station apparatus 1000 connected to the control apparatus 1100. The frame reception processing unit 1102 transmits the extracted transfer data to the upper layer processing unit 1103. Also, the frame reception processing unit 1102 transmits the extracted transfer data to the connected terminal monitoring unit 1106, the adjacent base station monitoring unit 1108, and the occupation rate reading unit 1110.

The upper layer processing unit 1103 receives the transfer data extracted by the frame reception processing unit 1102. The upper layer processing unit 1103 extracts the identifiers of the transmission source device and the destination device of the transfer data by processing the received transfer data. Each extracted identifier is, for example, an IP address. The extracted identifier of the transmission source device is, for example, the identifier of the wireless terminal device 700. The identifier of the extracted destination device is, for example, an identifier of a wireless terminal device 700 other than the wireless terminal device 700 that transmitted the transfer data, or an identifier of a communication device on the wide area network 500 side. When the extracted identifier of the destination device is the identifier of another wireless terminal device 700, the upper layer processing unit 1103 transmits the transfer data together with the extracted identifiers of the transmission source device and the destination device to the frame generation unit 1105. . When the extracted identifier of the destination device is the identifier of the communication device on the wide area network 500 side, the upper layer processing unit 1103 transmits the transfer data together with the extracted identifiers of the transmission source device and the destination device on the wide area network side interface. 1104.

The wide area network side interface 1104 receives the transfer data, the identifier of the transfer data transmission source device, and the identifier of the transfer data destination device from the upper layer processing unit 1103. The wide area network side interface 1104 generates a frame including the identifier of the frame transmission source device, the identifier of the frame destination device, and the received transfer data. The identifier of the frame transmission source device is generated based on the identifier of the transfer data transmission source device. The identifier of the destination device of the frame is generated based on the identifier of the destination device of the transfer data. The wide area network side interface 1104 generates an electrical signal including the received frame, and transmits the generated electrical signal to the wide area network 500.

Also, the wide area network side interface 1104 receives an electrical signal transmitted from a communication apparatus on the wide area network 500 side such as the control apparatus 300. The wide area network side interface 1104 extracts a frame by processing the received electrical signal. The wide area network side interface 1104 extracts various data from the extracted frame. Various data extracted by the wide area network side interface 1104 includes transfer data (packets), an identifier of a frame transmission source device, and an identifier of a frame destination device. Each identifier of the frame transmission source device and destination device is, for example, a MAC address. The frame transmission source device is, for example, an identifier of a communication device on the wide area communication network 500 side. The wide area communication network side interface 1104 transmits the extracted transfer data to the upper layer processing unit 1103.

The upper layer processing unit 1103 receives the transfer data extracted by the wide area network side interface 1104. The upper layer processing unit 1103 extracts the identifiers of the transmission source device and the destination device of the transfer data by processing the received transfer data. Each extracted identifier is, for example, an IP address. The extracted identifier of the transmission source device is, for example, the identifier of the communication device on the wide area communication network 500 side. The extracted identifier of the destination device is, for example, the identifier of the wireless terminal device 700. The higher layer processing unit 1103 transmits the transfer data to the frame generation unit 1105 together with the extracted identifiers of the transmission source device and the destination device.

The frame generation unit 1105 receives the transfer data, the identifier of the transfer data transmission source device, and the identifier of the transfer data destination device from the upper layer processing unit 1103. The frame generation unit 1105 generates a frame including the identifier of the frame transmission source device, the identifier of the frame destination device, and the received transfer data. Each identifier of the frame transmission source device and destination device is, for example, a MAC address. The identifier of the frame transmission source device is generated based on the identifier of the transmission data transmission source device. The identifier of the frame destination device is generated based on the identifier of the destination device of the transfer data. The frame destination device is, for example, the radio base station device 1000 connected to the radio terminal device 700 which is the transfer data destination device. The frame generation unit 1105 transmits the generated frame to the radio base station side interface 1101. In addition, the frame generation unit 1105 transmits the identifier of the destination device of the generated frame to the connection terminal monitoring unit 1106 together with the identifier of the destination device of the transfer data.

The radio base station side interface 1101 receives the frame generated by the frame generation unit 1105. The radio base station side interface 1101 generates an electrical signal including the received frame. The radio base station side interface 1101 transmits the generated electrical signal to the radio base station apparatus 1000 which is a frame destination apparatus.

The connection terminal monitoring unit 1106 monitors the connection terminal apparatus of each radio base station apparatus 1000 managed by the control apparatus 1100.

Specifically, the connection terminal monitoring unit 1106 receives the transfer data transmitted from the frame reception processing unit 1102. The connection terminal monitoring unit 1106 extracts the identifier of the connection terminal apparatus, the identifier of the radio base station apparatus 1000 connected to the connection terminal apparatus, and a flag indicating connection establishment or connection disconnection from the received transfer data. When the extracted flag is a flag indicating connection establishment, the connection terminal monitoring unit 1106 connects the identifier of the connection terminal apparatus with the identifier of the radio base station apparatus 1000 for each identifier of the radio base station apparatus 1000. The data is stored in the terminal storage unit 1107. When the extracted flag is a flag indicating disconnection, the connected terminal monitoring unit 1106 deletes the extracted identifier of the connected terminal device from the connected terminal storage unit 1107. FIG. 14 is an example of a connection terminal storage table provided in the control device according to the third embodiment. FIG. 14 illustrates a connection terminal storage table 11071 corresponding to the radio base station apparatus 1000 having the identifier “1A: 2B: 3C: 4D: 5E: 6F”. In the connection terminal storage unit 1107, a connection terminal storage table 11071 as shown in FIG. 14 is created for each radio base station apparatus 1000. Then, the connected terminal storage unit 1107 stores the identifier of the wireless terminal device 700 connected to the wireless base station device 1000 in the corresponding connected terminal storage table 11071.

Also, the connected terminal monitoring unit 1106 receives from the frame reception processing unit 1102 the identifier of the radio base station apparatus 1000 that is the frame transmission source apparatus and the transfer data included in the frame. The connected terminal monitoring unit 1106 extracts the identifier of the transmission data transmission source device from the received transfer data. The connection terminal monitoring unit 1106 refers to the connection terminal storage unit 1107 to determine whether or not the transmission source device of the received transfer data is the connection terminal device of the radio base station device 1000 that is the frame transmission source device. Confirm. For example, it is assumed that the transfer data transmission source device is confirmed to be a connection terminal device of the radio base station device 1000 which is a frame transmission source device. In this case, the connected terminal monitoring unit 1106 transmits the identifier of the connected terminal device that is the transmission data transmission source device and the identifier of the radio base station device 1000 that is the frame transmission source device to the traffic amount measurement unit 1112.

Further, the connected terminal monitoring unit 1106 receives from the frame generation unit 1105 the identifier of the radio base station device 1000 that is the frame destination device and the identifier of the radio terminal device 700 that is the destination device of the transfer data. The connection terminal monitoring unit 1106 refers to the connection terminal storage unit 1107 to check whether the destination device of the received transfer data is the connection terminal device of the radio base station apparatus 1000 that is the frame destination device. To do. For example, it is assumed that the transfer data destination device is confirmed to be a connection terminal device of the radio base station device 1000 that is a frame destination device. In this case, the connected terminal monitoring unit 1106 transmits the identifier of the connected terminal device that is the destination device of the transfer data and the identifier of the radio base station device 1000 that is the destination device of the frame to the traffic amount measuring unit 1112.

The adjacent base station monitoring unit 1108 monitors the identifier of the adjacent base station apparatus for the connection terminal apparatus connected to each radio base station apparatus 1000 managed by the control apparatus 1100. As described above, in the third embodiment, the adjacent base station apparatus refers to another radio base station apparatus 1000 to which a connection terminal apparatus can be connected other than the currently connected radio base station apparatus 1000.

Specifically, the adjacent base station monitoring unit 1108 receives the transfer data transmitted from the frame reception processing unit 1102. The adjacent base station monitoring unit 1108 extracts the identifier of the other area terminal device and the identifier of the radio base station device 1000 that identifies the other area terminal device from the received transfer data. The adjacent base station monitoring unit 1108 stores the extracted identifier of the radio base station device 1000 in the adjacent base station storage unit 1109 for each extracted identifier of the other area terminal device. The other area terminal device stored in the adjacent base station storage unit 1109 is a connection terminal device connected to a specific radio base station device 1000 managed by the control device 1100. The radio base station apparatus 1000 stored in the adjacent base station storage unit 1109 in association with the other area terminal apparatus is an adjacent base station apparatus to which the other area terminal apparatus can be connected. Therefore, the adjacent base station monitoring unit 1108 processes the information on the other area terminal devices transmitted from each radio base station device 1000, so that the information about the adjacent base station device for each connected terminal device is stored in the adjacent base station storage unit 1109. Remembered. For example, the adjacent base station storage unit 1109 stores the identifier of the adjacent base station device for each connected terminal device using a table having the same format as the adjacent base station storage table 9031 shown in FIG.

The occupation rate reading unit 1110 reads the radio space occupation rate calculated for the connected terminal device from the transfer data received from the radio base station device 1000 within a predetermined time, and uses the read radio space occupation rate as the occupation rate. The data is stored in the storage unit 1111. Specifically, the occupation rate reading unit 1110 receives the transfer data transmitted from the frame reception processing unit 1102 within a predetermined time. The occupancy rate reading unit 1110, from the received transfer data, the radio space occupancy rate, the identifier of the connected terminal device for which the radio space occupancy rate has been calculated, and the identifier of the radio base station device 1000 for which the radio space occupancy rate has been calculated Read. The occupation rate reading unit 1110 stores the read radio space occupation rate in the occupation rate storage unit 1111 in association with the read identifier of the connected terminal device for each read radio base station device 1000. FIG. 15 is an example of an occupancy rate storage table provided in the control device according to the third embodiment. FIG. 15 illustrates an occupation ratio storage table 11111 corresponding to the radio base station apparatus 1000 having the identifier “1A: 2B: 3C: 4D: 5E: 6F”. In the occupancy rate storage unit 1111, an occupancy rate storage table 11111 as shown in FIG. 15 is created for each radio base station apparatus 1000. Then, the occupation rate storage unit 1111 stores the wireless space occupation rate of the connection terminal apparatus in the corresponding occupation rate storage table 11111.

The traffic volume measuring unit 1112 measures the traffic volume within a predetermined time with respect to the connection terminal apparatus connected to each radio base station apparatus 1000 managed by the control apparatus 1100.

Specifically, the traffic amount measuring unit 1112 monitors the identifier of the radio base station apparatus 1000 that is a frame transmission source apparatus and the identifier of the connection terminal apparatus that is the transmission data transmission apparatus in the frame. Received from the unit 1106. Further, the traffic volume measuring unit 1112 receives the transfer data including the received identifier of the connected terminal device as the identifier of the transmission source device from the frame reception processing unit 1102. The traffic volume measuring unit 1112 measures the data volume of the received transfer data as the traffic volume for the connection terminal device indicated by the received identifier. The traffic volume measuring unit 1112 stores the measured traffic volume in the traffic volume storage unit 1113 in association with the received identifier of the connected terminal apparatus for each radio base station apparatus 1000 indicated by the received identifier. FIG. 16 is an example of a traffic amount storage table provided in the control device according to the third embodiment. FIG. 16 illustrates a traffic amount storage table 11131 corresponding to the radio base station apparatus 1000 having the identifier “1A: 2B: 3C: 4D: 5E: 6F”. In the traffic volume storage unit 1113, a traffic volume storage table 11131 as shown in FIG. 16 is created for each radio base station apparatus 1000. The traffic volume storage unit 1113 stores the traffic volume of the connected terminal device in the corresponding traffic volume storage table 11131.

Further, the traffic volume measuring unit 1112 receives from the connected terminal monitoring unit 1106 the identifier of the radio base station apparatus 1000 that is the frame destination device and the identifier of the connected terminal device that is the destination device of the transfer data in the frame. . Further, the traffic volume measuring unit 1112 receives the transfer data including the received identifier of the connected terminal device as the identifier of the destination device from the higher layer processing unit 1103. The traffic volume measuring unit 1112 measures the data volume of the received transfer data as the traffic volume for the connection terminal device indicated by the received identifier. The traffic volume measuring unit 1112 stores the measured traffic volume in the traffic volume storage unit 1113 in association with the received identifier of the connected terminal apparatus for each radio base station apparatus 1000 indicated by the received identifier.

The load distribution control unit 1114 totals the traffic volume for each connection terminal apparatus stored in the traffic volume storage unit 1113 for each radio base station apparatus 1000, so that the total traffic volume within a predetermined time is calculated for each radio base station apparatus 1000. To calculate. The load distribution control unit 1114 performs load distribution control on each radio base station apparatus 1000 using the calculated total traffic amount.

Specifically, the load distribution control unit 1114 determines whether the calculated total traffic volume exceeds a preset traffic volume threshold. When it is determined that the total traffic volume exceeds the traffic volume threshold, the load distribution control unit 1114 determines that the connection terminal apparatus having an adjacent base station apparatus that has a high radio space occupancy and can accommodate the corresponding traffic volume as a load distribution target. Specified as a connected terminal device. That is, the load distribution control unit 1114 first selects a connection terminal device having a high radio space occupation rate stored in the occupation rate storage unit 1111. The load distribution control unit 1114 next selects the connection terminal device in which the adjacent base station device is recorded in the adjacent base station storage unit 1109 among the selected connection terminal devices. Then, the load distribution control unit 1114 identifies, among the selected connection terminal devices, a connection terminal device having an adjacent base station device that can accommodate the traffic amount for the connection terminal device. The load distribution control unit 1114 generates transfer data including a load distribution instruction for the identified connection terminal apparatus, and generates a frame of the generated transfer data and the identifier of the radio base station apparatus 1000 connected to the connection terminal apparatus To the unit 1105. Further, the load distribution control unit 1114 deletes the identifier of the wireless terminal device 700 specified as the connection terminal device targeted for load distribution from the connection terminal storage unit 1107.

Further, when it is determined that the total traffic volume exceeds the traffic volume threshold even after the connection with all the connection terminal apparatuses having the adjacent base station apparatus is disconnected, the load distribution control unit 1114 Perform load balancing processing for. That is, the load distribution control unit 1114 identifies a connection terminal device that has a high radio space occupancy rate and does not have an adjacent base station device as a connection terminal device that is a load distribution target. The load distribution control unit 1114 generates transfer data including a load distribution instruction for the identified connection terminal apparatus, and generates a frame of the generated transfer data and the identifier of the radio base station apparatus 1000 connected to the connection terminal apparatus To the unit 1105. Further, the load distribution control unit 1114 deletes the identifier of the wireless terminal device 700 specified as the connection terminal device targeted for load distribution from the connection terminal storage unit 1107.

The frame generation unit 1105 receives, from the load distribution control unit 1114, transfer data including a load distribution instruction for the connection terminal device specified by the load distribution control unit 1114 and an identifier of the radio base station device 1000 connected to the connection terminal device. Receive. The frame generation unit 1105 generates a frame that includes the received transfer data and uses the received identifier as a frame destination device, and transmits the generated frame to the radio base station side interface 1101. The radio base station side interface 1101 transmits an electrical signal including the frame generated by the frame generation unit 1105.

The load applied to the radio base station apparatus 1000 is distributed to other radio base station apparatuses 1000 included in the second radio communication system 400 by the load distribution process performed by the control apparatus 1100 according to the third embodiment. By distributing the load on the radio base station apparatus 1000, the consumption of radio resources shared by the radio base station apparatus 1000 and the radio terminal apparatus 700 is reduced. As a result, the throughput in the first radio communication system 200 sharing the radio resources is improved, and the occurrence of a congestion state in the first radio communication system 200 is prevented.

In addition, in the load distribution processing by the control device 1100 according to the third embodiment, a connection terminal device having an adjacent base station device that can accommodate the corresponding traffic volume is preferentially selected as a connection terminal device that is a load distribution target. The Therefore, according to the load distribution processing according to the third embodiment, the certainty that the disconnected wireless terminal device 700 is connected to another wireless base station device 1000 is further improved, and the second wireless communication system Load balancing within 400 is more reliably performed.

FIG. 17 is an exemplary hardware configuration diagram of the control device according to the third embodiment. As shown in FIG. 17, the control device 1200 includes a processor 1201, a storage device 1202, a wireless base station network interface (NIF) circuit 1203, a wide area network network interface (NIF) circuit 1204, and a bus 1205. The processor 1201, the storage device 1202, the wireless base station network interface circuit 1203, and the wide area network network interface circuit 1204 are connected to each other via a bus 1205.

The processor 1201 is a logic circuit or arithmetic circuit that performs arithmetic processing such as a CPU or DSP. The processor 1201 includes a frame reception processing unit 1102, a higher layer processing unit 1103, a frame generation unit 1105, a connected terminal monitoring unit 1106, an adjacent base station monitoring unit 1108, an occupancy rate reading unit 1110, a traffic amount measuring unit 1112, and a load distribution control. Corresponds to portion 1114.

The storage device 1202 is a device that stores a processing program executed by the processor 1201, data used for processing by the processor 1201, and data of a processing result by the processor 1201. The storage device 1201 corresponds to the connection terminal storage unit 1107, the adjacent base station storage unit 1109, the occupation rate storage unit 1111, and the traffic amount storage unit 1113.

The wireless base station network interface circuit 1203 is a circuit that processes electrical signals transmitted to and received from the wireless base station apparatus 1000. The radio base station network interface circuit 1203 corresponds to the radio base station side interface 1101.

The network interface circuit 1204 for the wide area communication network is a circuit that processes electrical signals transmitted and received with a communication device (not shown) on the wide area communication network 500 side. The network interface circuit 1204 for the wide area network corresponds to the wide area network side interface 1104.

As an example of a communication control method according to the third embodiment, load distribution processing executed by the control device 1100 will be described. 18A to 18C are flowcharts of an exemplary load distribution process executed by the control device according to the third embodiment. Note that a series of load distribution processes as shown in FIGS. 18A to 18C may be repeatedly executed at predetermined time intervals. Also, the processing in each step shown in FIGS. 18A to 18C is not necessarily separated in terms of time, and may be performed in parallel.

When a series of load distribution processing is started (step S3001), the data in the occupation rate storage unit 1111 and the traffic amount storage unit 1113 is initialized by the load distribution control unit 1114. Then, the processes in steps S3002 to S3006 are performed on each radio base station apparatus 1000 managed by the control apparatus 1100.

Specifically, in step S3002, the adjacent base station monitoring unit 1108 receives the transfer data transmitted from the frame reception processing unit 1102. The adjacent base station monitoring unit 1108 extracts the identifier of the other area terminal device and the identifier of the radio base station device 1000 that identifies the other area terminal device from the received transfer data. The adjacent base station monitoring unit 1108 stores the extracted identifier of the radio base station device 1000 in the adjacent base station storage unit 1109 for each extracted identifier of the other area terminal device. As a result, the identifier of the adjacent base station device for each connected terminal device is recorded in the adjacent base station storage unit 1109.

The processing in steps S3003 to S3005 is repeated within a predetermined time each time the frame reception processing unit 1102 receives a frame transmitted from the radio base station apparatus 1000 via the radio base station side interface 1101. Further, the processing in steps S3003 to S3005 is repeated within a predetermined time each time the frame generation unit 1105 generates a frame including transfer data having the connection terminal device as the destination device and having the radio base station device 1000 as the destination device. It is.

Specifically, in step S3003, the occupation rate reading unit 1110 receives the transfer data extracted from the frame by the frame reception processing unit 1102. The occupancy rate reading unit 1110 receives the transfer data received from the wireless space occupancy rate, the identifier of the connection terminal device from which the radio space occupancy rate has been calculated, and the identifier of the radio base station device 1000 from which the radio space occupancy rate has been calculated. Read from. The occupancy rate reading unit 1110 associates the read radio space occupancy rate with the identifier of the connected terminal device, and stores it in the occupancy rate storage unit 1111 for each identifier of the radio base station device 1000.

In step S3004, the connected terminal monitoring unit 1106 receives from the frame reception processing unit 1102 the identifier of the radio base station device 1000 that is the frame transmission source device and the transfer data included in the frame. The connected terminal monitoring unit 1106 extracts the identifier of the transmission data transmission source device from the received transfer data. The connection terminal monitoring unit 1106 refers to the connection terminal storage unit 1107 to determine whether or not the transmission source device of the received transfer data is the connection terminal device of the radio base station device 1000 that is the frame transmission source device. Confirm. For example, it is assumed that the transfer data transmission source device is confirmed to be a connection terminal device of the radio base station device 1000 which is a frame transmission source device. In this case, the connected terminal monitoring unit 1106 transmits the identifier of the connected terminal device that is the transmission data transmission source device and the identifier of the radio base station device 1000 that is the frame transmission source device to the traffic amount measurement unit 1112.

In step S3005, the traffic volume measurement unit 1112 displays the identifier of the wireless base station device 1000 that is a frame transmission source device and the identifier of the connection terminal device that is the transmission data source device of the transfer data in the frame. 1106 is received. Further, the traffic volume measuring unit 1112 receives the transfer data including the received identifier of the connected terminal device as the transmission source device from the frame reception processing unit 1102. The traffic volume measuring unit 1112 measures the data volume of the received transfer data as the traffic volume for the connection terminal device indicated by the received identifier. For each received identifier of the radio base station apparatus 1000, the traffic volume measuring unit 1112 records the measured traffic volume in the traffic volume storage unit 1113 in association with the received identifier of the connected terminal device.

Alternatively, in step S3004, the connection terminal monitoring unit 1106 receives from the frame generation unit 1105 the identifier of the radio base station device 1000 that is the frame destination device and the identifier of the radio terminal device 700 that is the destination device of the transfer data. . The connection terminal monitoring unit 1106 refers to the connection terminal storage unit 1107 to check whether the destination device of the received transfer data is the connection terminal device of the radio base station apparatus 1000 that is the frame destination device. To do. For example, it is assumed that the transfer data destination device is confirmed to be a connection terminal device of the radio base station device 1000 that is a frame destination device. In this case, the connected terminal monitoring unit 1106 transmits the identifier of the connected terminal device that is the destination device of the transfer data and the identifier of the radio base station device 1000 that is the destination device of the frame to the traffic amount measuring unit 1112.

In step S3005, the traffic volume measurement unit 1112 receives from the connection terminal monitoring unit 1106 the identifier of the radio base station apparatus 1000 that is the frame destination device and the identifier of the connection terminal device that is the destination device of the transfer data in the frame. Receive. Further, the traffic volume measuring unit 1112 receives the transfer data including the received identifier of the connected terminal device as the identifier of the destination device from the higher layer processing unit 1103. The traffic volume measuring unit 1112 measures the data volume of the received transfer data as the traffic volume for the connection terminal device indicated by the received identifier. For each received identifier of the radio base station apparatus 1000, the traffic volume measuring unit 1112 records the measured traffic volume in the traffic volume storage unit 1113 in association with the received identifier of the connected terminal device.

When the processing in steps S3003 to S3005 is performed for a predetermined time, a series of load distribution processing proceeds to step S3006. In step S3006, the load distribution control unit 1114 sums the traffic volume for each connection terminal apparatus recorded in the traffic volume storage unit 1113 for each radio base station apparatus 1000, thereby calculating the total traffic volume for each radio base station apparatus 1000. To calculate. The load distribution control unit 1114 performs the first loop process in steps S3007 to S3025 for each radio base station apparatus 1000 using the calculated total traffic amount.

Specifically, the load distribution control unit 1114 determines whether or not the total traffic amount calculated for the radio base station apparatus 1000 selected in the first loop processing exceeds a preset traffic amount threshold value. Determination is made (step S3008). The predetermined traffic threshold value may be set for each radio base station apparatus 1000 based on the system capacity of each first radio communication system 200.

When it is determined that the total traffic volume is equal to or less than the traffic volume threshold (“NO” in step S3008), the load applied to the radio base station apparatus 1000 selected in the first loop processing is the other radio base station apparatus 1000. It does not have to be dispersed. Therefore, the series of load distribution processing ends (step S3026).

On the other hand, when it is determined that the total traffic volume exceeds the traffic volume threshold (“YES” in step S3008), the load applied to the radio base station apparatus 1000 selected in the first loop process is set to another radio base station apparatus. It is desirable to disperse to 1000. Therefore, a series of load distribution processing proceeds to step S3009.

In step S3009, the load distribution control unit 1114 uses the identifier of the connected terminal device recorded in the occupation rate storage unit 1111 for the radio base station device 1000 selected in the first loop process, and the corresponding radio space occupation rate is Sort in descending order. Then, the load distribution control unit 1114 performs the second loop processing between step S3010 and step S3018 in the order of the corresponding connected terminal devices with the highest radio space occupancy.

Specifically, the load distribution control unit 1114 determines whether or not there is an adjacent base station device in the connection terminal device selected in the second loop process by referring to the adjacent base station storage unit 1109 ( Step S3011).

When it is determined that there is no adjacent base station apparatus in the connection terminal apparatus selected in the second loop process (“NO” in step S3011), the load distribution control unit 1114 is selected in the second loop process. The identifier of the connected terminal device is held (step S3012). Also, the load distribution control unit 1114 increments the count number for the connected terminal device that does not have an adjacent base station device (step S3013). Then, the series of load distribution processing is returned to step S3011. That is, the load distribution control unit 1114 performs the process in step S3011 for the next connection terminal device in the order of the connection terminal devices with the highest radio space occupancy.

On the other hand, if it is determined that there is an adjacent base station device in the connection terminal device selected in the second loop processing (“YES” in step S3011), the processing proceeds to step S3014. In step S3014, the load distribution control unit 1114 determines whether there is a radio base station apparatus 1000 that can accommodate the traffic amount for the connection terminal apparatus selected in the second loop process. Specifically, the load distribution control unit 1114 acquires the traffic volume for the connection terminal device selected in the second loop process from the traffic volume storage unit 1113. The load distribution control unit 1114 adds the acquired traffic volume to the total traffic volume of each radio base station apparatus 1000, respectively. Then, the load distribution control unit 1114 determines whether or not there is a radio base station apparatus 1000 in which the total traffic amount after addition is equal to or less than a predetermined traffic threshold.

When it is determined that there is no radio base station apparatus 1000 that can accommodate the traffic volume for the connection terminal apparatus selected in the second loop process (“NO” in step S3014), the second loop for the connection terminal apparatus The process ends. This is because it is desirable that the load distribution target connection terminal device be specified preferentially among other connection terminal devices. Then, the series of load distribution processing is returned to step S3011. That is, the load distribution control unit 1114 performs the process in step S3011 for the next connection terminal device in the order of the connection terminal devices with the highest radio space occupancy.

On the other hand, if it is determined that there is a radio base station apparatus 1000 that can accommodate the traffic volume for the connection terminal apparatus selected in the second loop process (“YES” in step S3014), the process proceeds to step S3015. It is done. That is, in step S3015, the load distribution control unit 1114 identifies the connection terminal device as the connection terminal device to be load-balanced. This is because it is desirable that the identified connection terminal apparatus be changed in connection from the currently connected radio base station apparatus 1000 to another radio base station apparatus 1000 that can accommodate the amount of traffic for the connection terminal apparatus.

The load distribution control unit 1114 generates transfer data including a load distribution instruction for the identified connection terminal apparatus, and generates a frame of the generated transfer data and the identifier of the radio base station apparatus 1000 connected to the connection terminal apparatus To the unit 1105. Further, the load distribution control unit 1114 deletes the identifier of the wireless terminal device 700 specified as the connection terminal device targeted for load distribution from the connection terminal storage unit 1107.

The frame generation unit 1105 receives, from the load distribution control unit 1114, transfer data including a load distribution instruction for the connection terminal device specified by the load distribution control unit 1114 and an identifier of the radio base station device 1000 connected to the connection terminal device. Receive. The frame generation unit 1105 generates a frame that includes the received transfer data and uses the received identifier as a frame destination device, and transmits the generated frame to the radio base station side interface 1101. The radio base station side interface 1101 transmits an electrical signal including the frame generated by the frame generation unit 1105.

The electrical signal transmitted from the radio base station side interface 1101 is received by the radio base station apparatus 1000 connected to the load distribution target connection terminal apparatus. Radio base station apparatus 1000 extracts a load distribution instruction from transfer data in a frame included in the received electrical signal. The radio base station apparatus 1000 reads the identifier of the connection terminal apparatus targeted for load distribution from the extracted load distribution instruction, and forms a null point at the position where the connection terminal apparatus indicated by the read identifier exists. Control beamforming. As a result, the connection between the identified connection terminal device and radio base station device 1000 is disconnected.

The load distribution control unit 1114 recalculates the total traffic amount by subtracting the traffic amount for the wireless terminal device 700 specified as the load distribution target connection terminal device from the total traffic amount (step S3016). Then, the load distribution control unit 1114 determines whether or not the recalculated total traffic volume is equal to or less than the traffic volume threshold (step S3017).

When it is determined that the total traffic volume is equal to or less than the traffic volume threshold (“YES” in step S3017), the load applied to the radio base station apparatus 1000 is the other radio base station apparatus 1000 in the second radio communication system 400. It can be said that it was dispersed. Therefore, the series of load distribution processing ends (step S3026).

On the other hand, when it is determined that the total traffic volume exceeds the traffic volume threshold (“NO” in step S3017), the load applied to the radio base station apparatus 1000 is set to another radio base station apparatus 1000 in the second radio communication system 400. Further dispersion is desirable. Therefore, the second loop process is returned to step S3011. That is, the load distribution control unit 1114 performs the process in step S3011 for the next connection terminal device in the order of the connection terminal devices with the highest radio space occupancy.

When the second loop processing is performed for all the connected terminal devices, the series of load distribution processing proceeds to step S3019. In step S3019, the load distribution control unit 1114 has the corresponding wireless space occupancy recorded in the occupancy storage unit 1111 for the identifier held in step S3012, that is, the identifier of the connected terminal device that does not have an adjacent base station device. Sort in order. Then, the load distribution control unit 1114 performs the third loop processing between step S3020 and step S3024 in the order of connection terminal devices having a higher radio space occupancy corresponding to connection terminal devices that do not have adjacent base station devices. .

Specifically, in step S3021, the load distribution control unit 1114 identifies the connection terminal device selected in the third loop process as the connection terminal device targeted for load distribution. Then, the load distribution control unit 1114 generates transfer data including a load distribution instruction for the identified connection terminal apparatus, and generates the generated transfer data and the identifier of the radio base station apparatus 1000 connected to the connection terminal apparatus. Transmit to the frame generation unit 1105. Further, the load distribution control unit 1114 deletes the identifier of the wireless terminal device 700 specified as the connection terminal device targeted for load distribution from the connection terminal storage unit 1107.

The frame generation unit 1105 receives, from the load distribution control unit 1114, transfer data including a load distribution instruction for the connection terminal device specified by the load distribution control unit 1114 and an identifier of the radio base station device 1000 connected to the connection terminal device. Receive. The frame generation unit 1105 generates a frame that includes the received transfer data and uses the received identifier as a frame destination device, and transmits the generated frame to the radio base station side interface 1101. The radio base station side interface 1101 transmits an electrical signal including the frame generated by the frame generation unit 1105.

The electrical signal transmitted from the radio base station side interface 1101 is received by the radio base station apparatus 1000 connected to the load distribution target connection terminal apparatus. Radio base station apparatus 1000 extracts a load distribution instruction from transfer data in a frame included in the received electrical signal. The radio base station apparatus 1000 reads the identifier of the connection terminal apparatus targeted for load distribution from the extracted load distribution instruction, and forms a null point at the position where the connection terminal apparatus indicated by the read identifier exists. Control beamforming. As a result, the connection between the identified connection terminal device and radio base station device 1000 is disconnected.

The load distribution control unit 1114 recalculates the total traffic amount by subtracting the traffic amount for the wireless terminal device 700 specified as the load distribution target connection terminal device from the total traffic amount (step S3022). Then, the load distribution control unit 1114 determines whether or not the recalculated total traffic volume is equal to or less than the traffic volume threshold (step S3023).

When it is determined that the total traffic volume is equal to or less than the traffic volume threshold (“YES” in step S3023), the load applied to the radio base station apparatus 1000 is the other radio base station apparatus 1000 in the second radio communication system 400. It can be said that it was dispersed. Therefore, the series of load distribution processing ends (step S3026).

On the other hand, when it is determined that the total traffic volume exceeds the traffic volume threshold value (“NO” in step S3023), the load applied to the radio base station apparatus 1000 is set to another radio base station apparatus 1000 in the second radio communication system 400. Further dispersion is desirable. Therefore, the third loop process is returned to step S3021. That is, the load distribution control unit 1114 performs the process in step S <b> 3023 for the next connected terminal device in the order of the connected terminal devices with the highest radio space occupancy.

When the third loop process is performed for all the connected terminal apparatuses that do not have the adjacent base station apparatus, the first loop process for the radio base station apparatus 1000 selected in step S3007 ends (step S3025). Then, the series of load distribution processing is returned to step S3008, and the load distribution control unit 1114 performs first loop processing on the next radio base station apparatus 1000.

When the first loop process is performed on each radio base station apparatus 1000 managed by the control apparatus 1100, the series of load distribution processes ends (step S3026).

Thus, according to the load distribution process according to the third embodiment, the load applied to the radio base station apparatus 1000 is distributed to other radio base station apparatuses 1000 included in the second radio communication system 400. . By distributing the load on the radio base station apparatus 1000, the consumption of radio resources shared by the radio base station apparatus 1000 and the radio terminal apparatus 700 is reduced. As a result, the throughput in the first radio communication system 200 sharing the radio resources is improved, and the occurrence of a congestion state in the first radio communication system 200 is prevented.

Further, in the load distribution process according to the third embodiment, a connection terminal apparatus having an adjacent base station apparatus that can accommodate the corresponding traffic volume is preferentially selected as a connection terminal apparatus that is a load distribution target. Therefore, according to the load distribution process according to the third embodiment, the disconnected wireless terminal device 700 is more reliably connected to another wireless base station device 1000 in the second wireless communication system 400. The load distribution in the second wireless communication system 400 is more reliably performed.

The description given above with reference to FIGS. 11 to 18C is only an example of the load distribution process according to the third embodiment in which the control device 1100 executes the load distribution process in the second wireless communication system 400. In addition, various changes and additions can be made to the above-described apparatus configuration and processing.

For example, in the above description, each radio base station apparatus 1000 transmits information on another area terminal apparatus to the control apparatus 1100. The control apparatus 1100 receives information on the other area terminal apparatus from each radio base station apparatus 1000, and uses the received information to obtain information on the adjacent base station apparatus of the connection terminal apparatus connected to each radio base station apparatus 1000. get.

Instead of the configuration as described above, a configuration as described below may be used. As described above with reference to the second embodiment, the wireless terminal device 700 may have a function corresponding to the second connection method as standardized in IEEE802.11k and IEEE802.11v. In this case, the radio base station apparatus 1000 may be configured to identify an adjacent base station apparatus of the connection terminal apparatus, similarly to the radio base station apparatus 900. The radio base station apparatus 1000 may be configured to transmit information related to the adjacent base station apparatus of the connection terminal apparatus to the control apparatus 1100. Further, the control apparatus 1100 may be configured to receive information related to the adjacent base station apparatus of the connection terminal apparatus from each radio base station apparatus 1000 and store the received information. With such a configuration, the control device 1100 may perform load distribution processing according to the third embodiment. Even with such a configuration, the above-described effects can be obtained.

Also, for example, in the above description with reference to FIGS. 11 to 18C, the control device 1100 measures the traffic amount for each connection terminal device. Instead of such a configuration, similarly to the radio base station devices 600 and 900, the radio base station device 1000 may be configured to measure the traffic amount for each connection terminal device. The radio base station apparatus 1000 may be configured to transmit the traffic amount for each connection terminal apparatus to the control apparatus 1100. Further, the control apparatus 1100 may be configured to receive the traffic volume for each connection terminal apparatus from each radio base station apparatus 1000 and store the received traffic volume. With such a configuration, the control device 1100 may perform load distribution processing according to the third embodiment. Even with such a configuration, the above-described effects can be obtained.

Furthermore, the function (see FIG. 13) that the control device 1100 has in order to perform load distribution processing may be included in the specific radio base station device 1000 in the second radio communication system 400. That is, the specific radio base station apparatus 1000 may be configured to connect to another radio base station apparatus 1000 in the second radio communication system 400. In addition, the specific radio base station apparatus 1000 may be configured to receive various types of information used for load distribution processing from other radio base station apparatuses 1000. Examples of various information used for the load balancing process include, for example, identifiers of connection terminal devices, traffic amounts and radio space occupancy rates for each connection terminal device, and identifiers of other area terminal devices or identifiers of adjacent base station devices of connection terminal devices. Is mentioned. With such a configuration, the specific radio base station apparatus 1000 in the second radio communication system 400 may perform load distribution processing according to the third embodiment. Even with such a configuration, the above-described effects can be obtained.

Claims (12)

An occupancy ratio calculating unit that calculates a radio space occupancy ratio of frames transmitted and received between the radio base station apparatus and each radio terminal apparatus connected to the radio base station apparatus for each radio terminal apparatus;
Among the wireless terminal devices connected to the wireless base station device, the wireless terminal device is identified using the wireless space occupancy calculated by the occupancy calculating unit, and the identified wireless terminal device and the wireless base station And a first control unit that controls to disconnect the connection with the apparatus. The first control unit establishes connection with the radio base station device in descending order of the radio space occupancy calculated by the occupancy rate calculation unit among the radio terminal devices connected to the radio base station device. The radio base station apparatus according to claim 1, wherein the radio base station apparatus is specified as a radio terminal apparatus to be disconnected. From the amount of data in the frame that each wireless terminal device transmits to the wireless base station device and the amount of data in the frame that the wireless base station device transmits to each wireless terminal device, the wireless terminal device It has a traffic volume measurement unit that measures the traffic volume for each
The first control unit, when the total traffic amount obtained by summing the traffic amount for each wireless terminal device measured by the traffic amount measurement unit exceeds a predetermined value, The radio base station apparatus according to claim 1, wherein the connection with the radio base station apparatus is disconnected. The occupation ratio calculation unit calculates a radio space occupation ratio of the frame received by the radio base station apparatus and including an identifier of a radio terminal apparatus connected to the radio base station apparatus as an identifier of a transmission source apparatus The radio base station apparatus according to any one of claims 1 to 3, characterized in that: An occupancy ratio calculating unit that calculates a radio space occupancy ratio of frames transmitted and received between the radio base station apparatus and each radio terminal apparatus connected to the radio base station apparatus for each radio terminal apparatus;
A first control unit that identifies a radio terminal device using the radio space occupancy calculated by the occupancy rate calculation unit among the radio terminal devices connected to the radio base station device;
An antenna through which a radio signal including the frame is transmitted and received between the radio base station apparatus and each radio terminal apparatus;
A second controller that controls the direction and power of the beam formed by the antenna;
Including
The first control unit instructs the second control unit to form a beam for the antenna so as to form a null point at a position where the specified wireless terminal device exists,
The second control unit is a radio base station apparatus that forms the null point at a position where the specified radio terminal apparatus exists in accordance with an instruction of the beam formation by the first control unit. Receives a value of received power intensity for a signal transmitted from a radio base station apparatus other than the radio base station apparatus from each radio terminal apparatus, and transmits the signal with the received value exceeding a predetermined threshold. And further includes a monitoring unit that identifies the other wireless base station device for each wireless terminal device,
The first control unit includes the other radio base station device specified by the monitoring unit among the radio terminal devices connected to the radio base station device, and performs radio communication in descending order of the radio space occupancy rate. The radio base station apparatus according to claim 5, wherein a terminal apparatus is specified. A wireless communication system including a wireless base station device and a wireless terminal device connected to the wireless base station device,
The wireless base station device
Calculating the radio space occupancy rate of frames transmitted and received between the radio base station apparatus and each radio terminal apparatus connected to the radio base station apparatus for each radio terminal apparatus;
From the amount of data in the frame that each wireless terminal device transmits to the wireless base station device and the amount of data in the frame that the wireless base station device transmits to each wireless terminal device, the wireless terminal device Measure the amount of traffic
When the measured total traffic volume for each radio terminal apparatus exceeds a predetermined value, the radio space occupancy calculated in the radio terminal apparatus connected to the radio base station apparatus is Identifying a high wireless terminal device and controlling to disconnect the identified wireless terminal device and the wireless base station device;
Wireless communication system. The radio base station apparatus is specified by controlling the direction and power of a beam formed by an antenna through which a radio signal including the frame is transmitted and received between the radio base station apparatus and each radio terminal apparatus. The wireless communication system according to claim 7, wherein a null point is formed at a position where the wireless terminal device exists. Each of the wireless terminal devices transmits a received power intensity value for a signal transmitted from another wireless base station device other than the wireless base station device to the wireless base station device,
The wireless base station device
For each wireless terminal device, another wireless base station device that receives the value transmitted from each wireless terminal device and transmits the signal in which the received value exceeds a predetermined threshold is received for each wireless terminal device. Identify,
The radio terminal apparatus according to claim 7 or 8, wherein, among the radio terminal apparatuses connected to the radio base station apparatus, the radio terminal apparatus having the identified other radio base station apparatus and having a high radio space occupancy is identified. Wireless communication system. A communication control method executed by a radio base station apparatus,
Calculating the radio space occupancy rate of frames transmitted and received between the radio base station apparatus and each radio terminal apparatus connected to the radio base station apparatus for each radio terminal apparatus;
From the amount of data in the frame that each wireless terminal device transmits to the wireless base station device and the amount of data in the frame that the wireless base station device transmits to each wireless terminal device, the wireless terminal device Measure the amount of traffic
When the total amount of traffic totaled for each wireless terminal device measured by the traffic amount measuring unit exceeds a predetermined value, it is calculated in the wireless terminal device connected to the wireless base station device Identifying a radio terminal apparatus having a high radio space occupancy, and controlling to disconnect a connection between the identified radio terminal apparatus and the radio base station apparatus;
Communication control method. The specified wireless terminal device exists by controlling the direction and power of the beam formed by the antenna through which the wireless signal including the frame is transmitted and received between the wireless base station device and each wireless terminal device. A null point is formed at the position where
The communication control method according to claim 10. Received from each wireless terminal device a value of the strength of received power for signals transmitted from other wireless base station devices other than the wireless base station device,
For each wireless terminal device, specify another wireless base station device that has transmitted the signal with the received value exceeding a predetermined threshold,
Among the wireless terminal devices connected to the wireless base station device, the wireless terminal device having the specified other wireless base station device and having a high wireless space occupancy is specified as a load balancing target wireless terminal device ,
The communication control method according to claim 10 or 11.

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