JP5702247B2 - Wireless communication apparatus and wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication system in which one system band is shared by a plurality of wireless communication methods.

  Conventionally, various techniques relating to wireless communication have been proposed. For example, Patent Document 1 discloses a plurality of wireless communication methods for communication between a base station and a communication terminal, specifically, UTRA (UMTS Terrestrial Radio Access) -FDD (Frequency Division Duplex) method and UTRA-TDD (Time Division). A wireless communication system using a Duplex method is disclosed.

JP 2001-358644 A

  In the wireless communication system, it is desired to improve the communication performance of the wireless communication device used in the wireless communication system.

  Therefore, the present invention has been made in view of the above points, and an object thereof is to provide a technique capable of improving the communication performance of a wireless communication apparatus.

In order to solve the above-described problem, a wireless communication apparatus provided in a wireless communication system that shares a system band with a plurality of wireless communication systems, wherein the system band can be used in each of the plurality of wireless communication systems. A wireless communication unit capable of wirelessly communicating with a plurality of communication partner devices using the plurality of wireless communication methods, and a communication partner device capable of communicating with the plurality of wireless communication methods A communication quality acquisition unit that acquires communication qualities of the plurality of wireless communication methods when communicating with the wireless communication unit, and wireless communication used for communication with the communication partner device when the wireless communication unit communicates with the communication partner device If the wireless communication method with the best communication quality is used and there is no free bandwidth in the available bandwidth for the wireless communication method with the best communication quality, The free bandwidth, and a control unit to ensure the available bandwidth of the other radio communication scheme of the system band.

Further, in one aspect of the wireless communication device according to the present invention, the control unit uses an available bandwidth of a wireless communication method that the wireless communication unit uses for communication with a communication partner device as the wireless communication method. This is ensured by changing the wireless communication method used for communication with other communication partner devices communicating with the same wireless communication method .
Secure.

Further, in one aspect of the wireless communication apparatus according to the present invention, an occupancy rate determining unit that determines an occupancy rate in the system band for each of the plurality of usable bands is provided, and the occupancy rate determining unit includes the When the utilization rate of the available bandwidth of a certain wireless communication method among a plurality of wireless communication methods is smaller than the threshold value, the occupation rate of the available bandwidth is reduced.

Further, in one aspect of the wireless communication device according to the present invention, the control unit is configured so that the wireless communication unit can communicate with a communication partner device that can communicate with the plurality of wireless communication methods. When communication is performed using one of the wireless communication systems, the utilization rate for the usable bandwidth of the one wireless communication system is greater than the first threshold and the use of another wireless communication system When the utilization rate for the possible bandwidth is smaller than the second threshold value that is equal to or less than the first threshold value, the wireless communication method that the wireless communication unit uses for communication with the communication partner device is Change from one wireless communication method to the other wireless communication method.

The wireless communication system according to the present invention is a wireless communication system that shares a system band with a plurality of wireless communication methods, and includes a first wireless communication device and a plurality of second wireless communication devices that wirelessly communicate with the first wireless communication device. A wireless communication device, wherein the system band includes a plurality of usable bands that can be used in the plurality of wireless communication methods, respectively, and the first wireless communication device uses the plurality of wireless communication methods. A plurality of wireless communication methods when communicating with a wireless communication unit capable of wireless communication with the plurality of second wireless communication devices and a communication partner device capable of communicating with the plurality of wireless communication methods. When the communication quality acquisition unit for acquiring communication quality and the wireless communication unit communicate with the communication partner device, the wireless communication method used for communication with the communication partner device is the best communication quality. When the available bandwidth for the wireless communication method with the best communication quality is not available, the available bandwidth is secured from the available bandwidth of other wireless communication methods in the system bandwidth. And a control unit .

  ADVANTAGE OF THE INVENTION According to this invention, the communication performance of a radio | wireless communication apparatus can be improved.

It is a figure which shows the structure of a radio | wireless communications system. It is a figure which shows an example of a system band. It is a figure which shows an example of a system band. It is a figure which shows an example of a system band. It is a figure which shows the structure of a base station. It is a figure which shows an example of the occupation rate of each available band. It is a figure which shows an example of a usable system specific table. It is a figure which shows an example of a usage method specific table. It is a figure which shows an example of an occupation rate table. It is a figure which shows an example of a utilization rate table. It is a figure which shows the structure of a multi-method terminal. It is a figure which shows the structure of a single system terminal. It is a flowchart which shows operation | movement of a base station. It is a flowchart which shows operation | movement of a base station. It is a flowchart which shows operation | movement of a base station. It is a figure which shows the structure of the modification of a base station. It is a flowchart which shows operation | movement of the modification of a base station. It is a flowchart which shows operation | movement of the modification of a base station.

  FIG. 1 is a diagram showing a configuration of a wireless communication system 100 according to the present embodiment. In radio communication system 100 according to the present embodiment, a plurality of radio communication schemes, for example, two radio communication schemes are used. Specifically, for example, a combination of the UTRA-TDD scheme and the LTE (Long Term Evolution) TDD scheme, a combination of the UTRA-TDD scheme and the UTRA-FDD scheme, or a combination of the LTE TDD scheme and the LTE FDD scheme is used. Is done. Hereinafter, the two wireless communication methods used by the wireless communication system 100 according to the present embodiment are referred to as “first method” and “second method”.

  Further, in radio communication system 100 according to the present embodiment, system band 500 is shared by a plurality of radio communication schemes. That is, the system band 500 is composed of an available band that can be used for communication using the first method and an available band that can be used for communication using the second method. Hereinafter, the former usable bandwidth is referred to as “first method usable bandwidth”, and the latter usable bandwidth is referred to as “second method usable bandwidth”. In addition, when there is no need to particularly distinguish the first and second method usable bands, each is simply referred to as “available band”. Also, the wireless communication system is simply called “communication system”.

  FIG. 2 shows an example of the system band 500. As shown in FIG. 2, the system band 500 is continuous on the frequency axis and includes a first method usable band 501 and a second method usable band 502. In the present embodiment, as will be described later, the occupancy ratio of each available band in the system band 500 (the ratio occupied by each available band in the system band 500) can be changed. For example, the occupancy rates of the first and second method usable bands can be 40% and 60%, respectively, and the occupancy rates of the first and second method usable bands can be 30% and 70%, respectively.

  As shown in FIG. 3, the system band 500 may be composed of a plurality of partial frequency bands 500a and 500b that are arranged apart from each other on the frequency axis. In this case, each of the first and second method usable bands is arranged in one or both of the plurality of partial frequency bands 500a and 500b.

  In addition, each usable band does not need to be continuous on the frequency axis as in the example of FIG. 2, and as shown in FIG. 4, a plurality of partial frequency bands arranged apart from each other on the frequency axis. It may be constituted by. In the example of FIG. 4, the first method usable band 501 is composed of two partial frequency bands 501a and 501b that are arranged apart from each other on the frequency axis, and the second method usable band 502 is on the frequency axis. It consists of two partial frequency bands 502a and 502b that are arranged apart from each other.

  Returning to FIG. 1, the wireless communication system 100 includes a plurality of base stations 1 which are wireless communication devices. Each base station 1 can perform two-way wireless communication with a plurality of communication terminals 2 that are wireless communication devices using a plurality of communication methods. The service area 150 of each base station 1 partially overlaps the service area 150 of the neighboring base station 1. In FIG. 1, only four base stations 1 are shown, so there are only two or three neighboring base stations 1 for one base station 1, but in reality one base station 1 For example, there may be six neighboring base stations 1 for the station 1.

  The plurality of base stations 1 are connected to a network (not shown) and can communicate with each other through the network. Further, a server device (not shown) is connected to the network, and each base station 1 can communicate with the server device through the network.

<Base station configuration>
FIG. 5 is a diagram showing the configuration of each base station 1. As illustrated in FIG. 5, the base station 1 includes a wireless communication unit 10 that can wirelessly communicate with a plurality of communication terminals 2 using a plurality of communication methods, and a control unit 13 that controls the wireless communication unit 10. And.

  The wireless communication unit 10 includes a first communication unit 11 that wirelessly communicates with the communication terminal 2 using the first method, and a second communication unit 12 that wirelessly communicates with the communication terminal 2 using the second method. . The 1st communication part 11 receives the transmission signal from the communication terminal 2 which communicates using a 1st system with the antenna 11a. The first communication unit 11 performs amplification processing, down-conversion, A / D conversion processing, and the like on the reception signal from the antenna 11a to generate and output a baseband reception signal.

  Similarly, the 2nd communication part 12 receives the transmission signal from the communication terminal 2 which communicates using a 2nd system with the antenna 12a. Then, the second communication unit 12 performs amplification processing, down-conversion, A / D conversion processing, and the like on the reception signal at the antenna 12a, and generates and outputs a baseband reception signal.

  Further, the first communication unit 11 performs D / A conversion processing, up-conversion, amplification processing, and the like on the baseband transmission signal generated by the control unit 13 according to the first method, so that the carrier band The transmission signal is generated. Then, the first communication unit 11 wirelessly transmits the generated transmission signal of the carrier band from the antenna 11a.

  Similarly, the second communication unit 12 performs D / A conversion processing, up-conversion, amplification processing, and the like on the baseband transmission signal generated by the control unit 13 according to the second method, and carries Generate a transmission signal in the band. Then, the second communication unit 12 wirelessly transmits the generated transmission signal of the carrier band from the antenna 12a.

  The control unit 13 includes a CPU (Central Processing Unit), a DSP (Digital Signal Processor), a memory, and the like. In the control unit 13, the CPU and the DSP execute the program in the memory, so that the transmission / reception processing unit 14, the radio resource allocation unit 15, the communication method determination unit 16, the occupation rate determination unit 17, the utilization rate calculation unit 18, and the storage Functional blocks such as the part 19 are formed.

  The transmission / reception processing unit 14 performs demodulation processing or the like on the reception signal output from the first communication unit 11 and acquires control data, user data, and the like included in the reception signal. The transmission / reception processing unit 14 performs demodulation processing or the like on the reception signal output from the second communication unit 12 and acquires control data, user data, and the like included in the reception signal.

  Further, the transmission / reception processing unit 14 generates a transmission signal according to the first method to be transmitted to the communication terminal 2 that communicates using the first method. Then, the transmission / reception processing unit 14 performs a modulation process or the like on the generated transmission signal to generate a baseband transmission signal, and inputs the baseband transmission signal to the first communication unit 11. Thereby, the base station 1 wirelessly transmits a transmission signal corresponding to the first scheme to the communication terminal 2 that communicates using the first scheme.

  Further, the transmission / reception processing unit 14 generates a transmission signal according to the second method to be transmitted to the communication terminal 2 that communicates using the second method. Then, the transmission / reception processing unit 14 performs modulation processing or the like on the generated transmission signal to generate a baseband transmission signal, and inputs the baseband transmission signal to the second communication unit 12. Thereby, the base station 1 wirelessly transmits a transmission signal corresponding to the second method to the communication terminal 2 that communicates using the second method.

  The radio resource allocation unit 15 allocates radio resources used by the radio communication unit 10 in communication with the communication terminal 2 (more specifically, individual communication) to the communication terminal 2 with which the radio communication unit 10 communicates. Specifically, the radio resource allocation unit 15 allocates a usage band, a usage time zone, and the like used by the radio communication unit 10 for communication with the communication terminal 2 to the communication terminal 2 with which the radio communication unit 10 communicates. . When allocating the use band to the communication terminal 2, the radio resource allocation unit 15 can use the available band (the first method usable band or the second method usable) for the communication method used by the communication terminal 2 for communication. The used bandwidth is allocated from the available bandwidth.

  The transmission / reception processing unit 14 generates a transmission signal to be transmitted to the communication terminal 2 based on the radio resource allocated to the communication terminal 2 by the radio resource allocation unit 15 and also transmits the transmission signal at a timing based on the radio resource. Is input to the wireless communication unit 10. Accordingly, a transmission signal to be transmitted to the communication terminal 2 is transmitted from the wireless communication unit 10 using the wireless resource allocated to the communication terminal 2.

  The transmission / reception processing unit 14 also generates and outputs a transmission signal including control data for notifying the communication terminal 2 of the radio resource allocated to the communication terminal 2 by the radio resource allocation unit 15. Thereby, the communication terminal 2 can know the radio resources used in downlink communication and uplink communication with the base station 1. Therefore, the communication terminal 2 can appropriately receive the signal addressed to the own device from the base station 1 and can transmit the signal using the radio resource allocated to the own device in the base station 1.

  The communication method determination unit 16 determines a communication method used by the wireless communication unit 10 for communication with the communication terminal 2. Here, in the present embodiment, it is possible to use the communication terminal 2 that can use only one of the first method and the second method, and both the first method and the second method. Communication terminal 2 exists. Hereinafter, the former communication terminal 2 is referred to as “single mode terminal 2a”, and the latter communication terminal 2 is referred to as “multiple mode terminal 2b”. When the wireless communication unit 10 communicates with the single method terminal 2a, the communication method determination unit 16 determines the communication method used by the wireless communication unit 10 for communication with the single method terminal 2a as the single method terminal. The communication method (first method or second method) used by 2a for communication is assumed. On the other hand, when the wireless communication unit 10 communicates with the multiple method terminal 2b, the communication method determination unit 16 determines the communication method used by the wireless communication unit 10 for communication with the multiple method terminal 2b. 2b selects from a plurality of communication methods (first and second methods) that can be used for communication.

  When the wireless communication unit 10 communicates with the multi-method terminal 2b, the transmission / reception processing unit 14 determines the communication method used by the wireless communication unit 10 for communication with the multi-method terminal 2b, as determined by the communication method determination unit 16. A transmission signal including control data for notifying the multi-method terminal 2b is generated and output. Thereby, the communication method used for communication with the base station 1 is notified to the multi-method terminal 2b, and the multi-method terminal 2b communicates with the base station 1 using the communication method.

  The occupancy rate determination unit 17 determines the occupancy rate in the system band for each of the first method usable band and the second method usable band. For example, the occupation rate determination unit 17 sets the occupation rate of the first method available band to 70% and the occupation rate of the second method available band to 30%. FIG. 6 is a diagram illustrating a state in which the occupation rates of the first method usable band 501 and the second method usable band 502 are set to 70% and 30%, respectively. In the example of FIG. 6, the radio communication unit 10 has more frequency bands when communicating with the communication terminal 2 using the first method than when communicating with the communication terminal 2 using the second method. Can be used. Note that the occupancy rate determination unit 17 adopts, for example, 50% as the initial values of the occupancy rates of the first method usable band and the second method usable band.

  The utilization rate calculation unit 18 obtains the utilization rate for each of the first method usable band and the second method usable band. That is, the utilization rate calculation unit 18 obtains the ratio of the frequency band used by the wireless communication unit 10 in communication with the communication terminal 2 for each of the first method usable band and the second method usable band. In the utilization rate calculation unit 18, for example, the utilization rate for the first method usable band is calculated to be 40%, and the utilization rate for the second method usable band is determined to be 60%.

  The storage unit 19 stores an available method specifying table 19a, a used method specifying table 19b, an occupation rate table 19c, and a utilization rate table 19d. 7 to 10 are diagrams showing these tables, respectively.

  The usable method specifying table 19a describes which communication method of the first and second methods can be used by each communication terminal 2 with which the base station 1 communicates. Specifically, as shown in FIG. 7, the usable method specification table 19 a includes, for each communication terminal 2 with which the base station 1 communicates, the terminal ID of the communication terminal 2 (identification for identifying the communication terminal 2). Information) and communication methods that can be used by the communication terminal 2 are registered in association with each other. In the example of FIG. 7, only the first method can be used for the communication terminal 2 with the terminal ID “1”, and only the second method can be used for the communication terminals 2 with the terminal IDs “2” and “4”. The communication terminal 2 with the terminal ID “3” can use both the first and second methods.

  In the usage method specification table 19b, for each communication terminal 2 with which the wireless communication unit 10 is currently communicating, a communication method used by the wireless communication unit 10 for communication with the communication terminal 2 is described. Specifically, as illustrated in FIG. 8, the usage method specification table 19 b includes, for each communication terminal 2 with which the wireless communication unit 10 is communicating, the terminal ID of the communication terminal 2 and the communication terminal 2. The communication method used by the wireless communication unit 10 in communication is associated and registered. In the example of FIG. 8, the communication terminal 2 with the terminal ID “1” uses the first method, and the communication terminals 2 with the terminal IDs “2”, “3”, and “4” use the second method. doing.

  In the occupancy rate table 19c, as shown in FIG. 9, the occupancy rates for the first method usable bandwidth and the second method usable bandwidth determined by the occupancy rate determining unit 17 are described.

  In the utilization rate table 19d, as shown in FIG. 10, the utilization rates in the first method usable band and the second method usable band obtained by the utilization rate calculating unit 18 are described. When the above-described usage method specification table 19b or occupancy rate table 19c is updated, the usage rate calculation unit 18 obtains the usage rates for the first mode available bandwidth and the second mode available bandwidth, and uses them. The rate table 19d is updated.

  In the base station 1 according to the present embodiment, the communication method determination unit 16 refers to various tables stored in the storage unit 19 and determines the communication method used by the wireless communication unit 10 for communication with the communication terminal 2. decide. Further, the occupation rate determination unit 17 refers to various tables stored in the storage unit 19 and determines the occupation rate for each of the first method usable band and the second method usable band. The operations of the communication method determination unit 16 and the occupation rate determination unit 17 will be described in detail later.

<Configuration of communication terminal>
FIG. 11 is a diagram showing the configuration of the multi-method terminal 2b. As shown in FIG. 11, the multi-method terminal 2 b includes a wireless communication unit 20 that performs wireless communication with the base station 1 and a control unit 23 that controls the wireless communication unit 20.

  The wireless communication unit 20 includes a first communication unit 21 that wirelessly communicates with the base station 1 using the first method, and a second communication unit 22 that wirelessly communicates with the base station 1 using the second method. . The first communication unit 21 receives a transmission signal transmitted from the base station 1 using the first method by the antenna 21a. The first communication unit 21 performs amplification processing, down-conversion, A / D conversion processing, and the like on the reception signal from the antenna 21a to generate and output a baseband reception signal.

  Similarly, the 2nd communication part 22 receives the transmission signal which the base station 1 transmits using a 2nd system with the antenna 22a. Then, the second communication unit 22 performs amplification processing, down-conversion, A / D conversion processing, and the like on the reception signal from the antenna 22a to generate and output a baseband reception signal.

  In addition, the first communication unit 21 performs D / A conversion processing, up-conversion processing, amplification processing, and the like on the baseband transmission signal generated by the control unit 23 in accordance with the first method, so that the carrier band The transmission signal is generated. Then, the first communication unit 21 wirelessly transmits the generated transmission signal of the carrier band from the antenna 21a.

  Similarly, the second communication unit 22 performs D / A conversion processing, up-conversion, amplification processing, and the like on the baseband transmission signal generated by the control unit 23 according to the second method, and carries Generate a transmission signal in the band. Then, the second communication unit 22 wirelessly transmits the generated transmission signal in the carrier band from the antenna 22a.

  The control unit 23 includes a CPU, a DSP, a memory, and the like. Various functions in the control unit 23 are realized by the CPU and the DSP executing programs in the memory. When notified from the base station 1 that the first method is used, the control unit 23 performs a demodulation process on the reception signal output from the first communication unit 21 and is included in the reception signal. Get control data and user data. On the other hand, when notified from the base station 1 that the second method is to be used, the control unit 23 performs a demodulation process or the like on the reception signal output from the second communication unit 22, and receives the reception signal. Control data, user data, etc. included in.

  Further, when notified from the base station 1 that the first scheme is used, the control unit 23 generates a transmission signal corresponding to the first scheme. Then, the control unit 23 performs modulation processing on the generated transmission signal to generate a baseband transmission signal, and inputs the baseband transmission signal to the first communication unit 21. As a result, a transmission signal corresponding to the first scheme is wirelessly transmitted to the base station 1 from the multiple scheme terminal 2b. On the other hand, when notified from the base station 1 that the second method is used, the control unit 23 generates a transmission signal corresponding to the second method. Then, the control unit 23 performs modulation processing or the like on the generated transmission signal to generate a baseband transmission signal, and inputs the baseband transmission signal to the second communication unit 22. As a result, a transmission signal corresponding to the second method is wirelessly transmitted to the base station 1 from the multi-method terminal 2b.

  As described above, the multi-method terminal 2b communicates with the base station 1 using the communication method that the base station 1 has decided to use in communication with the multi-method terminal 2b.

  FIG. 12 is a diagram showing a configuration of the single mode terminal 2a. As illustrated in FIG. 12, the single-mode terminal 2 a includes a wireless communication unit 25 that performs wireless communication with the base station 1 and a control unit 26 that controls the wireless communication unit 25.

  The wireless communication unit 25 receives a transmission signal transmitted from the base station 1 using an antenna 25a using a communication method that can be used by itself. The wireless communication unit 25 performs amplification processing, down-conversion, A / D conversion processing, and the like on the reception signal from the antenna 25a, and generates and outputs a baseband reception signal. The wireless communication unit 25 performs a D / A conversion process, an up-conversion process, an amplification process, and the like on the baseband transmission signal generated by the control unit 26 to generate a transmission signal in the carrier band. Then, the wireless communication unit 25 wirelessly transmits the generated transmission signal of the carrier band from the antenna 25a.

  The control unit 26 includes a CPU, a DSP, a memory, and the like. Various functions in the control unit 26 are realized by the CPU and the DSP executing programs in the memory. The control unit 26 performs demodulation processing or the like on the reception signal output from the wireless communication unit 25, and acquires control data, user data, and the like included in the reception signal. In addition, the control unit 26 generates a transmission signal corresponding to an available communication method. The control unit 26 modulates the generated transmission signal to generate a baseband transmission signal, and inputs the baseband transmission signal to the wireless communication unit 25. Thereby, the single mode terminal 2a transmits a signal to the base station 1 using an available communication mode (first mode or second mode).

<Connection operation with a single terminal at a base station>
Next, the operation of the base station 1 when the base station 1 connects to the single mode terminal 2a will be described. FIG. 13 is a flowchart showing the operation in the base station 1. Hereinafter, the single method terminal 2a to be described is referred to as “target single method terminal 2a”.

  When the base station 1 connects to the target single mode terminal 2a, as shown in FIG. 13, in step s1, the communication mode determination unit 16 selects a communication mode that can be used by the target single mode terminal 2a. The wireless communication unit 10 determines the communication method to be used for communication with the target single method terminal 2a. Hereinafter, a communication method that the wireless communication unit 10 determines to use for communication with the communication terminal 2 is referred to as a “used communication method”. When the target single mode terminal 2a starts communication with the base station 1 (at the time of initial connection with the base station 1), the target single mode terminal 2a notifies the base station 1 of a communication mode that can be used by itself.

  Next, in step s2, the communication method determination unit 16 uses the terminal ID of the target single method terminal 2a and the communication that can be used by the target single method terminal 2a with respect to the usable method specification table 19a in the storage unit 19. Register the method in association with it. As a result, the usable method specifying table 19a is updated.

  Next, in step s3, the radio resource allocation unit 15 determines whether there is a vacant band in the usable bandwidth of the used communication scheme (the first scheme usable bandwidth or the second scheme usable bandwidth) for the target single scheme terminal 2a. Determine whether. If it is determined in step s3 that there is a free band, in step s4, the communication method determination unit 16 associates the terminal ID and the used communication method of the target single method terminal 2a with the use method specifying table 19b. sign up. As a result, the usage method specification table 19b is updated. The radio resource allocation unit 15 determines that the target single mode terminal 2a and the base station 1 can communicate with each other when there is an available bandwidth in the usable communication mode for the target single mode terminal 2a. Then, a use band is allocated from the free band to the target single mode terminal 2a.

  On the other hand, if it is determined in step s3 that there is no free bandwidth, in step s5, the base station 1 reserves free bandwidth in the available bandwidth of the used communication method for the target single mode terminal 2a. Secure process is performed. FIG. 14 is a flowchart showing the free bandwidth securing process.

  As shown in FIG. 14, in the free bandwidth securing process, first, in step s51, the occupancy rate determination unit 17 determines the occupancy rate for the available bandwidth of the used communication method for the target single mode terminal 2a (hereinafter, “target It is determined whether or not it can be increased.

  Here, in the present embodiment, in order to prevent the base station 1 from communicating with one of the communication terminal 2 communicating with the first scheme and the communication terminal 2 communicating with the second scheme at all, A minimum occupancy rate that cannot be further reduced is defined for each of the occupancy rates of the first and second system usable bands. The minimum occupation ratio is set to 20%, for example. The occupancy rate determination unit 17 refers to the occupancy rate table 19c, and when the occupancy rates for the available bandwidths of communication methods other than the communication method used for the target single mode terminal 2a are all the minimum occupancy rates, It is determined that the occupation rate cannot be increased.

  Furthermore, the occupancy rate determination unit 17 refers to the usage rate table 19d, and when the usage rates for the available bandwidths of communication methods other than the used communication method for the target single mode terminal 2a are all 100%. It is determined that the target occupation rate cannot be increased.

  On the other hand, the occupancy rate determination unit 17 has an available bandwidth whose occupancy rate is not the lowest occupancy rate in the available bandwidth of the communication method other than the used communication method for the target single mode terminal 2a, and the use When there is an available bandwidth whose utilization rate is not 100% in the available bandwidth of a communication method other than the communication method, it is determined that the target occupation rate can be increased.

  If it is determined in step s51 that the target occupancy rate can be increased, in step s52, the occupancy rate determination unit 17 is a communication method other than the communication method used for the target single mode terminal 2a and is used. The occupation rate for the available bandwidth of the communication method in which the occupation rate for the available bandwidth is not the minimum occupation rate and the utilization rate for the available bandwidth is not 100% is reduced. At this time, while occupying the frequency band used in the usable band, the occupation ratio for the usable band is reduced so that the occupation ratio for the usable band is not smaller than the minimum occupation ratio. Then, the occupancy rate determination unit 17 increases the target occupancy rate so that the sum of the occupancy rates for the available bandwidths of the plurality of communication methods that can be used by the base station 1 becomes 100%. For example, if the communication method used for the target single mode terminal 2a is the first mode and the occupancy rates of the first and second mode available bands are both 50% before the execution of step s52, the step In s52, for example, the occupancy rate of the second method available band is changed from 50% to 40%, and the occupancy rate (target occupancy rate) of the first method available band is changed from 50% to 60%.

  As described above, when there is no available bandwidth in the available communication method for the target single mode terminal 2a, the available bandwidth is secured in the available bandwidth by increasing the occupation rate of the available bandwidth. be able to. Therefore, the base station 1 can communicate with the target single mode terminal 2a using the vacant band. As a result, the communication performance of the base station 1 is improved. The radio resource allocating unit 15 allocates a use band to the target single mode terminal 2a from the free band secured in this way in the usable bandwidth of the used communication mode for the target single mode terminal 2a.

  When step s52 is executed, in step s53, the occupancy rate determination unit 17 updates the occupancy rate table 19c based on the change of the occupancy rate in step s52.

  Next, in step s54, the communication method determining unit 16 registers the terminal ID of the target single method terminal 2a and the used communication method in association with each other in the use method specifying table 19b. As a result, the usage method specification table 19b is updated.

  If it is determined in step s51 described above that the target occupancy rate cannot be increased, the occupancy rate determination unit 17 refers to the available method identification table 19a in the storage unit 19 in step s55 and the base station 1 communicates. It is determined whether the communication terminal 2 in the middle is only the single mode terminal 2a. In step s55, when it is determined that the communication terminal 2 with which the base station 1 is communicating is not only the single mode terminal 2a, that is, it is determined that the multi-type terminal 2b exists in the communication terminal 2 with which the base station 1 is communicating. Then, in step s56, the communication method determination unit 16 can change the used communication method for the multi-method terminal 2b communicating using the same communication method as the used communication method for the target single method terminal 2a. It is determined whether or not. In other words, the communication method determination unit 16 determines the available bandwidth used by the multiple method terminal 2b that communicates with the base station 1 using the same communication method as the used communication method for the target single method terminal 2a. On the other hand, it is determined whether or not the usable bandwidth of the used communication method for the expression terminal 2a can be changed to the usable bandwidth of a communication method other than the used communication method.

  In step s56, when all the utilization ratios for the usable bandwidths of the communication methods other than the used communication method for the target single method terminal 2a are 100%, the communication method determining unit 16 selects the same communication method as the used communication method. It is determined that the communication method used for the multi-method terminal 2b that is using and communicating cannot be changed. On the other hand, the communication method determination unit 16 uses the available bandwidth of a communication method other than the used communication method for the target single method terminal 2a when there is an available bandwidth whose utilization rate is not 100%. It is determined that the used communication method for the multi-method terminal 2b communicating using the same communication method as the communication method can be changed.

  If it is determined in step s56 that the used communication method for the multiple method terminal 2b communicating using the same communication method as the used single method terminal 2a cannot be changed, the target single method terminal The available bandwidth is not secured in the available bandwidth of the used communication method for 2a, and the available bandwidth securing process ends. In this case, the target single mode terminal 2a cannot be connected to the base station 1.

  On the other hand, when it is determined in step s56 that the used communication method for the multi-method terminal 2b communicating using the same communication method as that for the target single method terminal 2a can be changed, in step s57. The communication method determination unit 16 changes the used communication method for at least one multi-method terminal 2b communicating using the same communication method as the used communication method of the target single method terminal 2a. For example, when the used communication method for the target single method terminal 2a is the first method, the communication method determination unit 16 uses at least one of the plurality of methods communicating with the wireless communication unit 10 using the first method. The communication method used for the terminal 2b is changed from the first method to the second method.

  In this way, when there is no available bandwidth in the usable communication method for the target single-method terminal 2a, the use for the multiple-method terminal 2b communicating using the same communication method as the used communication method. By changing the communication method, the frequency band used when the multi-method terminal 2b communicates using the same communication method as the communication method used for the target single-method terminal 2a is not used. An available bandwidth is secured in the available bandwidth of the used communication method for the single method terminal 2a. Therefore, the base station 1 can communicate with the target single mode terminal 2a using the vacant band. As a result, the communication performance of the base station 1 is improved. The radio resource allocating unit 15 allocates a use band to the target single mode terminal 2a from the free band secured in this way in the usable bandwidth of the used communication mode for the target single mode terminal 2a. In addition, the radio resource allocation unit 15 allocates a use band from the available bandwidth of the usable communication method after the change to the multi-method terminal 2b whose use communication method has been changed.

  If it is determined in step s55 described above that the communication terminal 2 with which the base station 1 is communicating is only the single mode terminal 2a, the communication mode used by the multiple mode terminal 2b cannot be changed. On the other hand, the available bandwidth is not secured in the available bandwidth of the used communication method for the type terminal 2a, and the available bandwidth securing process ends. In this case, the target single mode terminal 2a cannot be connected to the base station 1.

  When step s57 is executed, in step s58, the communication method determination unit 16 updates the usage method specification table 19b based on the change in the communication method used by the multi-method terminal 2b performed in step s58. Further, the communication method determining unit 16 registers the terminal ID of the target single method terminal 2a and the used communication method in association with the use method specifying table 19b, and updates the use method specifying table 19b.

  In step s57, when the use communication method of the multi-method terminal 2b is changed, the transmission / reception processing unit 14 sets the changed use communication method (the newly determined use communication method) to the multi-method terminal 2b. A transmission signal including control data for notification is generated and output. Thereby, the changed communication method used is notified to the multi-method terminal 2b, and thereafter, the multi-method terminal 2b communicates with the base station 1 using the changed communication method used.

  In the example of FIG. 14, steps s55 to s58 may not be executed. In this case, if it is determined in step s51 that the target occupancy rate cannot be increased, the target single mode terminal 2a cannot connect to the base station 1, and the free bandwidth securing process ends.

  In the example of FIG. 14, steps s51 to s54 do not have to be executed. In the free bandwidth securing process in this case, step s55 is first executed.

  Further, as described above, when the available bandwidth for the used communication method of the target single method terminal 2a is secured by changing the used communication method of the multi-method terminal 2b, the base station 1 The multi-method terminal 2b is notified of the changed communication method used, and the multi-method terminal 2b needs to change the communication method used based on an instruction from the base station 1.

  On the other hand, when the available bandwidth is secured in the available bandwidth by increasing the occupancy ratio of the available bandwidth for the communication method used by the target single mode terminal 2a, the free bandwidth is secured. Thus, the base station 1 does not need to control the communication terminal 2 in particular, and the communication terminal 2 does not need to perform special processing. Therefore, in this case, processing at the base station 1 and the communication terminal 2 can be reduced.

<Connection operation with multiple terminals at base station>
Next, the operation of the base station 1 when the base station 1 connects to the multi-method terminal 2b will be described. FIG. 15 is a flowchart showing the operation in the base station 1. Hereinafter, the target multi-method terminal 2b is referred to as “target multi-method terminal 2b”.

  When the base station 1 connects to the target multi-method terminal 2b, as shown in FIG. 15, in step s11, the communication method determination unit 16 notifies the target multi-method terminal 2b, which is notified from the target multi-method terminal 2b. A plurality of communication methods (first and second methods) that 2b can use are confirmed. Hereinafter, a communication method that can be used by the target multi-method terminal 2b is referred to as an “usable communication method”. Then, in step s12, the communication method determination unit 16 compares the terminal ID of the target multi-method terminal 2b and the plurality of usable communication for the target multi-method terminal 2b with respect to the usable method specifying table 19a in the storage unit 19. Register the method in association with it. As a result, the usable method specifying table 19a is updated.

  Next, in step s13, the communication method determination unit 16 refers to the utilization rate table 19d, and there is an available bandwidth having a free bandwidth in the available bandwidths of the plurality of usable communication methods for the target multi-method terminal 2b. It is determined whether or not to do. If it is determined in step s13 that there is no available band having a free band among the available bands of the plurality of usable communication systems for the target multi-system terminal 2b, the target multi-system terminal 2b Will not be able to connect to.

  On the other hand, if it is determined in step s13 that there is an available bandwidth having a free bandwidth among the available bandwidths of the plurality of available communication methods for the target multi-method terminal 2b, the communication method is determined in step s14. The unit 16 determines whether or not there is one available bandwidth having a vacant bandwidth among the available bandwidths of the plurality of usable communication methods.

  If it is determined in step s14 that there is one available bandwidth having a free bandwidth among the available bandwidths of the plurality of usable communication methods for the target multi-method terminal 2b, the communication method determination is performed in step s15. The unit 16 sets the communication method corresponding to the available bandwidth having the vacant bandwidth as the communication method used for the target multi-method terminal 2b. Then, the communication method determining unit 16 registers the terminal ID of the target multi-method terminal 2b and the used communication method in association with the used method specifying table 19b. As a result, the usage method specification table 19b is updated.

  On the other hand, if it is determined in step s14 that there is not one available bandwidth having a free bandwidth among the available bandwidths of the plurality of usable communication methods for the target multiple-method terminal 2b, that is, When it is determined that there are a plurality of usable bands having free bands in the usable bands of the plurality of usable communication systems for the system terminal 2b, the communication system determination unit 16 refers to the utilization rate table 19d, Among the plurality of usable bands, a communication method corresponding to the usable band having the lowest utilization rate is selected. For example, when there is a free band in both the first and second method usable bands, and the utilization rate of the first method usable band is smaller than the utilization rate of the second method usable band, The first method corresponding to the first method available band with the smaller utilization rate is selected. Then, the communication method determination unit 16 sets the selected communication method as the communication method used for the target multi-method terminal 2b. Thereafter, the communication method determination unit 16 executes Step s15 and registers the terminal ID of the target multi-method terminal 2b and the used communication method in association with the used method specifying table 19b.

  As described above, in the present embodiment, when there are a plurality of usable bands having free bands in the usable bands of the plurality of usable communication systems for the target multi-system terminal 2b, the plurality of usable systems can be used. The communication method corresponding to the usable bandwidth with the lowest utilization rate among the bands is the communication method used for the target multi-method terminal 2b. Therefore, it can suppress that the difference of a utilization factor becomes large between the useable bands of the some communication system which can be used by the base station 1. FIG. Therefore, in the base station 1, it can suppress that it becomes difficult to connect with the communication terminal 2 which communicates using a specific communication system.

<Changing the occupancy rate of the available bandwidth when the usage rate has decreased>
In the base station 1 according to the present embodiment, the occupancy rate determination unit 17 determines that the utilization rate for the available bandwidth of a certain communication method among the plurality of communication methods that can be used by the wireless communication unit 10 is lower than the threshold value. When it becomes smaller, the occupancy rate of the available bandwidth is reduced. For example, when the usage rate for the available bandwidth of a certain communication method becomes smaller than 20%, the occupation rate determination unit 17 reduces the occupation rate of the available bandwidth by 20%.

  When the utilization rate for the available bandwidth of a certain communication method is small, it can be considered that there are not many communication terminals 2 that communicate using the certain communication method in the vicinity of the base station 1. In such a case, by reducing the occupancy rate of the usable bandwidth of the certain communication method, the occupancy rate of the usable bandwidth of the communication method different from the certain communication method can be increased. Can be used effectively. For example, when the usage rate of the first method available band becomes smaller than 20%, the occupation rate of the first method available band is reduced by 20%, and the occupation rate of the second method available band is set to 20%. System bandwidth is effectively used by increasing it by%.

<Change of communication method used by multiple terminals based on available bandwidth usage>
In the base station 1 according to the present embodiment, the communication method determination unit 16 uses the utilization rate of the available communication method of the multi-method terminal 2b with which the wireless communication unit 10 communicates to be more than the first threshold value. The utilization rate for the usable bandwidth of communication methods other than the used communication method that can be used for communication by the multi-method terminal 2b is larger than the second threshold value less than or equal to the first threshold value. In this case, the communication method used by the multi-method terminal 2b is changed to the other communication method.

  The communication method determination unit 16 uses, for example, a utilization rate of the first method available band (first method available band) used by the multiple method terminal 2b with which the wireless communication unit 10 communicates for communication greater than 80%. In addition, when the utilization rate of the second system usable band (second system usable band) becomes smaller than 20%, the communication system used by the multi-system terminal 2b is changed from the first system to the second system. It is supposed to be.

  As described above, when the utilization rate of the available bandwidth of the currently used communication method for the multi-method terminal 2b is large for the multi-method terminal 2b with which the wireless communication unit 10 is communicating, the use of the multi-method terminal 2b is used. By changing the communication method to another communication method corresponding to an available bandwidth with a low utilization rate, the system bandwidth can be effectively used. Therefore, in the base station 1, it can suppress that it becomes difficult to connect with the communication terminal 2 which communicates using a specific communication system.

<Various modifications>
<First Modification>
In the above-described free bandwidth securing process shown in FIG. 14, it is first determined whether or not the target occupancy can be increased in step s51, but before step s51, the radio resource allocation unit 15 of the base station 1 The communication system used by the target single mode terminal 2a is narrowed by narrowing the use band that the wireless communication unit 10 allocates to another communication terminal 2 that is communicating in the same communication mode as that used by the target single mode terminal 2a. It may be determined whether an available bandwidth can be secured in the available bandwidth.

  Specifically, the radio resource allocation unit 15 first uses the currently allocated usage for each communication terminal 2 with which the radio communication unit 10 is communicating in the same communication scheme as that of the target single scheme terminal 2a. Check if the bandwidth is the minimum required bandwidth. Here, the minimum required bandwidth means a used bandwidth that should be allocated to the communication target communication terminal 2 as a minimum. The radio resource allocation unit 15 determines the minimum necessary bandwidth for each communication terminal 2. For example, the minimum required bandwidth for the communication terminal 2 that performs video data communication with the base station 1 is a relatively large value, and the minimum necessary bandwidth for the communication terminal 2 that performs voice data communication with the base station 1. The bandwidth is a relatively small value.

  The radio resource allocation unit 15 is such that all the used bands currently allocated to the communication terminals 2 with which the radio communication unit 10 is communicating in the same communication scheme as that of the target single scheme terminal 2a are the minimum necessary bands. In this case, it is determined that an available bandwidth cannot be secured in the available bandwidth of the communication method used by the target single mode terminal 2a.

  On the other hand, the wireless resource allocating unit 15 requires the currently allocated bandwidth to be the minimum in each communication terminal 2 in which the wireless communication unit 10 is communicating using the same communication method as that of the target single method terminal 2a. When there is a communication terminal 2 that is not a band, it is determined that a free band can be secured in the usable band of the communication method used by the target single mode terminal 2a.

  If the radio resource allocating unit 15 determines that an available bandwidth cannot be secured in the usable bandwidth of the communication method used by the target single mode terminal 2a, the above-described step s51 is executed, and the occupancy rate determination unit 17 sets the target occupancy rate. Determine whether it can be increased. Thereafter, processing similar to the processing in FIG. 14 is performed.

  On the other hand, if the radio resource allocating unit 15 determines that an available band can be secured in the usable band of the communication method used by the target single mode terminal 2a, the radio communication unit 10 is the same as the communication method used by the target single mode terminal 2a. The communication terminal 2 that is communicating with the communication method, and the use band assigned to the communication terminal 2 whose currently assigned use band is not the minimum required band is narrowed, and the communication method used by the target single method terminal 2a is reduced. Secure free bandwidth in available bandwidth. And the radio | wireless resource allocation part 15 allocates a use band with respect to the object single method terminal 2a from the free band ensured in the usable band of the use communication method about the object single method terminal 2a.

  In this way, when there is no available band in the usable communication method for the target single method terminal 2a, the wireless communication unit 10 communicates with the same communication method as the used communication method of the target single method terminal 2a. By narrowing the use band allocated to the other communication terminals 2 that are present, a free band is secured in the usable band of the use communication system of the target single mode terminal 2a, and the base station 1 uses the free band to On the other hand, it can communicate with the expression terminal 2a. As a result, the communication performance of the base station 1 is improved.

<Second Modification>
In the above description, when the base station 1 connects to the multi-method terminal 2b, among the plurality of usable communication methods for the multi-method terminal 2b, it can be used corresponding to the available bandwidth with the lowest utilization rate. Although the communication method is the communication method used by the multi-method terminal 2b, the usable communication method having the best communication quality may be the communication method used by the multi-method terminal 2b. Below, the base station 1 which concerns on this modification is demonstrated.

  FIG. 16 is a block diagram showing a configuration of the base station 1 according to this modification. As shown in FIG. 16, the base station 1 according to the present modification is such that, in the base station 1 shown in FIG. 5 described above, the control unit 13 further includes a communication quality acquisition unit 50 as a functional block.

  When the wireless communication unit 10 communicates with the multi-method terminal 2b, the communication quality acquisition unit 50 uses the available communication method for each of the plurality of usable communication methods for the multi-method terminal 2b. Acquires the communication quality when communicating with the multi-method terminal 2b. For example, the communication quality acquisition unit 50 instructs the multi-method terminal 2b to communicate with one usable communication method through the transmission / reception processing unit 14 and the wireless communication unit 10. And the communication quality acquisition part 50 calculates | requires communication quality based on the received signal from the multi-system terminal 2b which communicates by one usable communication system. The communication quality acquisition unit 50 performs this process for each of a plurality of usable communication methods of the multi-method terminal 2b. As the communication quality, for example, SINR (Signal to Interference and Noise power Ratio) or EVM (Error Vector Magnitude) is required.

  FIG. 17 is a flowchart showing an operation in the base station 1 when the base station 1 according to this modification connects to the target multi-method terminal 2b. As illustrated in FIG. 17, in the base station 1, similarly to the above-described step s <b> 11, in step s <b> 21, the communication method determination unit 16 is notified from the target multi-method terminal 2 b by the plurality of target multi-method terminals 2 b. Check the available communication methods. Next, in step s22, the communication method determination unit 16 associates the terminal ID of the target multi-method terminal 2b with the plurality of usable communication methods for the target multi-method terminal 2b in the usable method specifying table 19a. And register.

  Next, in step s23, the communication quality acquisition unit 50, when each of the plurality of usable communication systems for the target multi-system terminal 2b communicates with the multi-system terminal 2b using the usable communication system. Get communication quality.

  Next, in step s24, the communication method determination unit 16 uses the available communication method with the best communication quality acquired in step s23 among the plurality of usable communication methods for the target multi-method terminal 2b (hereinafter “best communication”). It is determined whether there is a free bandwidth in the available bandwidth of the “method”.

  If it is determined in step s24 that the available bandwidth of the best communication method is free, the communication method determination unit 16 determines the best communication method and the wireless communication unit 10 communicates with the target multi-method terminal 2b in step s25. The communication method used in Then, the communication method determining unit 16 registers the terminal ID of the target multi-method terminal 2b and the used communication method in association with the use method specifying table 19b.

  On the other hand, if it is determined in step s24 that there is no available bandwidth in the best communication scheme, in step s26, the base station 1 reserves a free bandwidth in the available bandwidth for the best communication scheme. Secure process is performed. FIG. 18 is a flowchart showing the free bandwidth securing process in step s26.

  As shown in FIG. 18, in the free bandwidth securing process in step s26, first, in step s261, the occupancy rate determination unit 17 uses the best communication method of the target multi-method terminal 2b in the same manner as in step s51 described above. It is determined whether or not the occupation rate for the possible bandwidth can be increased.

  If it is determined in step s261 that the occupation ratio of the usable bandwidth of the best communication method of the target multi-method terminal 2b can be increased, in step s262, the communication method determination unit 16 determines the target multi-method terminal 2b. The best communication method is the communication method used by the target multi-method terminal 2b. In step s263, the occupancy rate determination unit 17 is a communication method other than the used communication method (best communication method) for the target multi-method terminal 2b in the same manner as in the above-described step s52. The occupation ratio for the usable bandwidth of the communication method in which the occupation ratio is not the minimum occupation ratio and the utilization ratio for the usable bandwidth is not 100% is reduced. Then, the occupancy rate determination unit 17 can use the best communication method of the target multi-method terminal 2b so that the total sum of the occupancy rates for the available bands of the plurality of communication methods that can be used by the base station 1 becomes 100%. Increase the occupancy rate for the bandwidth.

  As described above, when there is no available bandwidth in the available bandwidth of the best communication method for the target multi-method terminal 2b, the available bandwidth is secured in the available bandwidth by increasing the occupancy rate of the available bandwidth. Can do. Therefore, the base station 1 can communicate with the target multi-method terminal 2b using the vacant bandwidth. The radio resource allocating unit 15 allocates a use band to the target multi-method terminal 2b from the free band thus secured in the available band of the used communication method (best communication method) for the target multi-method terminal 2b. .

  When step s263 is executed, in step s264, the occupancy rate determination unit 17 updates the occupancy rate table 19c based on the change in the occupancy rate in step s263. Next, in step s265, the communication method determination unit 16 registers the terminal ID of the target multi-method terminal 2b and the used communication method in association with each other in the use method specifying table 19b.

  If it is determined in step s261 described above that the occupancy rate of the available bandwidth of the best communication method for the target multi-method terminal 2b cannot be increased, the occupancy rate determination unit 17 sets the usable method specifying table 19a in step s266. Referring to it, it is determined whether the communication terminal 2 with which the base station 1 is communicating is only the single mode terminal 2a. If it is determined in step s266 that the communication terminal 2 with which the base station 1 is communicating is not the single method terminal 2a, in step s267, the communication method determination unit 16 performs wireless communication in the same manner as in step s56 described above. The communication unit 10 determines whether or not the communication method used for the multi-method terminal 2b that is communicating using the same communication method as the communication method used for the target multi-method terminal 2b can be changed.

  If it is determined in step s267 that the used communication method for the multi-method terminal 2b communicating using the same communication method as that for the target multi-method terminal 2b can be changed, the communication method is determined in step s268. The determination unit 16 sets the best communication method of the target multi-method terminal 2b as the communication method used by the target multi-method terminal 2b. In step s269, the communication method determination unit 16 performs at least one multi-method terminal 2b communicating using the same communication method as the used communication method of the target multi-method terminal 2b, as in step s57 described above. Change the communication method used.

  Thus, in the case where there is no available bandwidth in the available bandwidth of the best communication method for the target multi-method terminal 2b, communication in use for the multi-method terminal 2b communicating using the same communication method as the best communication method. By changing the method, the frequency band used when the multi-method terminal 2b communicates using the same communication method as the communication method used for the target multi-method terminal 2b is not used. A free band is generated in the usable band of the used communication method for the terminal 2b. Therefore, the base station 1 can communicate with the target multi-method terminal 2b using the vacant band. The radio resource allocating unit 15 allocates a use band to the target multi-method terminal 2b from the free band thus secured in the available band of the used communication method (best communication method) for the target multi-method terminal 2b. . In addition, the radio resource allocation unit 15 allocates a use band from the available bandwidth of the usable communication method after the change to the multi-method terminal 2b whose use communication method has been changed.

  When step s269 is executed, in step s270, the communication method determination unit 16 updates the use method identification table 19b based on the change in the communication method used by the multi-method terminal 2b performed in step s269. Furthermore, the communication method determination unit 16 registers the terminal ID of the target multi-method terminal 2b and the used communication method in association with the use method specifying table 19b.

  In step s269, when the communication method used by the multi-method terminal 2b is changed, the transmission / reception processing unit 14 transmits a transmission signal including control data for notifying the multi-method terminal 2b of the changed communication method. Is generated and output. Thereby, the changed communication method used is notified to the multi-method terminal 2b, and then the multi-method terminal 2b communicates with the base station 1 using the changed communication method used.

  In step s266 described above, when it is determined that the communication terminal 2 with which the base station 1 is communicating is only the single mode terminal 2a, in step s267 described above, the same communication method used for the target multiple mode terminal 2b. If it is determined that the communication method used for the multi-method terminal 2b communicating using the communication method cannot be changed, the base station 1 executes step s271.

  In step s271, the communication method determination unit 16 is a usable communication method other than the best communication method among the plurality of usable communication methods for the target multi-method terminal 2b, and the usable bandwidth is available. The communication method is determined as the communication method used by the target multi-method terminal 2b. At this time, when there are a plurality of usable communication methods having available bandwidths in the usable bandwidth, among the usable communication methods, the usable communication method having the best communication quality acquired in step s23 is selected. The communication method used by the target multi-method terminal 2b may be determined.

  It should be noted that, in a plurality of usable communication methods for the target multi-method terminal 2b, there is a usable communication method other than the best communication method, and there is no usable communication method in which an available bandwidth exists in the usable bandwidth. Therefore, the target multi-method terminal 2b cannot connect to the base station 1.

  When the used communication method of the target multi-method terminal 2b is determined in step s271, in step s272, the communication method determining unit 16 determines the terminal ID and the used communication of the target multi-method terminal 2b with respect to the use method specifying table 19b. Register the methods in association with each other.

  As described above, among the plurality of usable communication methods for the multi-method terminal 2b, the usable communication method having the best communication quality is set as the use communication method of the multi-method terminal 2b, so that the base station 1 and the plurality of communication methods can be used. Communication performance with the system terminal 2b can be further improved.

  Note that steps s266 to s270 may not be executed in the example of FIG. In this case, if it is determined in step s261 that the occupation rate of the usable bandwidth of the best communication method of the target multi-method terminal 2b cannot be increased, step s271 is executed.

  In the example of FIG. 18, steps s261 to s265 do not have to be executed. In the free bandwidth securing process in this case, step s266 is first executed.

  Similarly to the first modification described above, before step s261, the radio resource allocation unit 15 of the base station 1 communicates with the radio communication unit 10 in the same communication scheme as the best communication scheme of the target multi-method terminal 2b. It may be determined whether or not a free band can be secured in the usable band of the best communication method by narrowing the use band allocated to the other communication terminals 2. In this case, if the radio resource allocation unit 15 determines that the available bandwidth of the best communication scheme of the target multi-method terminal 2b cannot be secured, the above-described step s261 is executed, and the processing in FIG. The same processing is performed. On the other hand, when the radio resource allocating unit 15 determines that an available bandwidth can be secured in the available bandwidth of the best communication method of the target multi-method terminal 2b, the best communication method becomes the communication method used by the target multi-method terminal 2b. The radio resource allocation unit 15 allocates to the communication terminal 2 with which the radio communication unit 10 is communicating in the same communication scheme as the best communication scheme, and the currently allocated use band is not the minimum necessary band. The available bandwidth is narrowed, and a free bandwidth is secured in the usable bandwidth of the best communication method. And the radio | wireless resource allocation part 15 allocates a use band with respect to the object multi-system terminal 2b from the vacant band ensured in the usable band of the best communication system about the object multi-system terminal 2b.

  If there is not much difference in the communication quality acquired by the communication quality acquisition unit 50 with respect to a plurality of usable communication methods for the target multi-method terminal 2b, steps s24 to s26 are not executed and the above-described FIG. As shown in FIG. 4, in the plurality of usable communication methods for the target multi-method terminal 2b, the usable communication method corresponding to the usable bandwidth with the lowest utilization rate may be used as the communication method used by the target multi-method terminal 2b.

<Other variations>
In the above example, the base station 1 can use two communication methods for communication with the communication terminal 2, but it may be possible to use three or more communication methods. For example, the base station 1 may be able to use three communication methods for communication with the communication terminal 2, that is, the UTRA-TDD method, the LTE TDD method, and the LTE FDD method.

  In the above description, the case where the present invention is applied to the wireless communication system 100 including the base station 1 and the communication terminal 2 has been described. However, the present invention is not limited to this, and the present invention includes a plurality of wireless communication devices. Any wireless communication system that is provided can be applied.

DESCRIPTION OF SYMBOLS 1 Base station 2 Communication terminal 10 Wireless communication part 15 Radio | wireless resource allocation part 16 Communication system determination part 17 Occupancy rate determination part 50 Communication quality acquisition part 100 Wireless communication system 500 System band 501 1st system available band 502 2nd system available Band

Claims (5)

A wireless communication device provided in a wireless communication system that shares a system band with a plurality of wireless communication methods,
The system band includes a plurality of usable bands that can be used in the plurality of wireless communication methods,
A wireless communication unit capable of wirelessly communicating with a plurality of communication partner devices using the plurality of wireless communication methods;
A communication quality acquisition unit that acquires communication quality of the plurality of wireless communication methods when communicating with a communication partner apparatus capable of communicating with the plurality of wireless communication methods;
When the wireless communication unit communicates with the communication partner device, the wireless communication method used for communication with the communication partner device is the wireless communication method with the best communication quality and the wireless with the best communication quality. When there is no available bandwidth in the available bandwidth for the communication method, the controller secures the available bandwidth from the available bandwidth of other wireless communication methods in the system bandwidth;
A wireless communication device. The wireless communication device according to claim 1,
The control unit communicates the available bandwidth of the wireless communication method used by the wireless communication unit for communication with the communication partner device in another wireless communication method using the same wireless communication method as the wireless communication method. A wireless communication device secured by changing a wireless communication method used for communication with the device. A wireless communication device according to any one of claims 1 and 2 ,
An occupancy rate determination unit that determines an occupancy rate in the system band for each of the plurality of available bands;
The occupancy rate determining unit reduces the occupancy rate of the available bandwidth when a usage rate of an available bandwidth of a certain wireless communication method among the plurality of wireless communication methods is smaller than a threshold value. apparatus. The wireless communication device according to claim 3,
The control unit communicates with a communication partner apparatus capable of communicating with the plurality of wireless communication methods by using one wireless communication method among the plurality of wireless communication methods. In this case, the utilization rate for the usable bandwidth of the one wireless communication method is larger than the first threshold value, and the utilization rate for the usable bandwidth of the other wireless communication method is the first threshold value. When the state is smaller than the second threshold below, the wireless communication method used by the wireless communication unit for communication with the communication partner device is changed from the one wireless communication method to the other wireless communication method. A wireless communication device. A wireless communication system that shares a system band with a plurality of wireless communication methods,
A first wireless communication device;
A plurality of second wireless communication devices that wirelessly communicate with the first wireless communication device;
With
The system band includes a plurality of usable bands that can be used in the plurality of wireless communication methods,
The first wireless communication device is:
A wireless communication unit capable of wirelessly communicating with the plurality of second wireless communication devices using the plurality of wireless communication methods;
A communication quality acquisition unit that acquires communication quality of the plurality of wireless communication methods when communicating with a communication partner apparatus capable of communicating with the plurality of wireless communication methods;
When the wireless communication unit communicates with the communication partner device, the wireless communication method used for communication with the communication partner device is the wireless communication method with the best communication quality and the wireless with the best communication quality. When there is no available bandwidth in the available bandwidth for the communication method, the controller secures the available bandwidth from the available bandwidth of other wireless communication methods in the system bandwidth;
A wireless communication system.

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