Wireless communication method and wireless communication system

Abstract

To improve the efficiency of radio resource utilization for a wireless communication system as a whole, the present invention provides a wireless communication method in which a wireless base station executes a transmission process for broadcasting a connection condition of the wireless base station, a management process for managing connections with wireless terminals that request connection to the wireless base station on the basis of the connection condition, the management using a blockchain shared by a plurality of wireless base stations, a calculation process for using ledger information from the blockchain to calculate a normalized congestion level of other wireless base stations, and a changing process for changing the connection condition of the wireless base station on the basis of the normalized congestion level.

Description

Technical Field

[0001] The present invention relates to a wireless communication method and a wireless communication system.

Background Art

[0002] In connection control between a wireless base station and a wireless terminal, a wireless communication system is known that uses blockchain technology to perform distributed processing of connection control (see, for example, Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional technology, since a wireless terminal (user terminal) autonomously determines the connection destination wireless base station, wireless terminals that connect to a specific wireless base station (for example, a wireless base station with a low connection cost) are biased, and the utilization efficiency of the wireless resources of the entire wireless communication system may decrease.

[0005] An embodiment of the present invention has been made in view of the above problems, and improves the utilization efficiency of the wireless resources of the entire wireless communication system.

Means for Solving the Problems

[0006] To solve the above problems, a wireless communication method according to an embodiment of the present invention includes a transmission process in which a wireless base station broadcasts the connection conditions of the wireless base station, and a connection with a wireless terminal that requests connection to the wireless base station based on the connection conditions is managed using a blockchain shared by a plurality of wireless base stations. A management process, a calculation process of calculating a normalized congestion degree of other wireless base stations using the ledger information of the blockchain, and a change process of changing the connection conditions of the wireless base station based on the normalized congestion degree are executed.

Effects of the Invention

[0007] According to an embodiment of the present invention, the utilization efficiency of wireless resources of the entire wireless communication system can be improved.

Brief Description of the Drawings

[0008]

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Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention (this embodiment) will be described with reference to the drawings. The embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments.

[0010] <Overview> First, the outline of the wireless communication system using blockchain, which is the premise of this embodiment, will be described. The wireless communication system is a system that can connect a radio terminal to a radio base station without centralized management by performing connection processing in a decentralized manner using blockchain technology during the connection processing between the radio base station and the radio terminal.

[0011] (Outline of the process) FIG. 15 is a diagram for explaining the outline of the processing of a wireless communication system using a blockchain. In the wireless communication system, in the connection process where the wireless terminal 20 is connected to the wireless base station 10, transaction data 2 is created between the wireless base station 10 and the wireless terminal 20 (step S1). For example, the wireless terminal 20 receives the connection conditions broadcast by the wireless base station 10 and checks the communication quality of the wireless communication network provided by the wireless base station 10, the connection cost, etc. On the other hand, the wireless base station 10 checks whether the wireless terminal 20 has sufficient payment ability, etc. When an agreement on the connection conditions is obtained between the wireless base station 10 and the wireless terminal 20, the wireless base station 10 records the content of the agreement in the transaction data 2.

[0012] Note that the communication quality of the wireless communication network provided by the wireless base station 10 includes, for example, throughput, total data volume, etc. The wireless terminal 20 may agree to the connection conditions when the communication quality provided by the wireless base station 10 satisfies all the communication quality requirements of the wireless terminal 20. Or, the wireless terminal 20 may agree to the connection conditions when the communication quality provided by the wireless base station 10 satisfies some of the communication quality requirements of the wireless terminal 20.

[0013] The wireless base station 10 diffuses the transaction data 2 created in the connection process to the nodes participating in the blockchain network 30 (step S2). The blockchain network 30 includes a plurality of nodes that share a blockchain (decentralized ledger) in which the transaction data 2 is collectively recorded in block units and a plurality of blocks are recorded in time series. The plurality of nodes include a plurality of wireless base stations 10 constituting the wireless communication system. Note that the plurality of nodes may include nodes other than the wireless base station 10 (computers, wireless terminals, etc.).

[0014] When the blockchain network 30 is notified of the transaction data 2, some nodes participating in the blockchain network 30 (for example, the radio base stations 10x) generate block 3 together with other transaction data (step S3). Further, after generating block 3, the blockchain network 30 adds the generated block 3 to the blockchain 40 of each node included in the blockchain network 30 (step S4).

[0015] The blockchain 40 of each node holds the added block, and when a predetermined number of blocks (verification blocks) are further added to the blockchain, the contract is established by accepting the held block (step S5). After the contract is established, the radio base station 10 starts communication with the wireless terminal 20 (step S6).

[0016] By the above processing, the wireless communication system can execute the connection process between the radio base station 10 and the wireless terminal 20 by distributed control without relying on a control station or the like that centrally controls the wireless communication system.

[0017] (Regarding the problem) In the above wireless communication system, it is a control procedure led by the wireless terminal (user terminal) 20 in which the wireless terminal 20 checks the connection conditions transmitted by one or more radio base stations 10 and determines the radio base station 10 to which to request a connection.

[0018] However, in the control procedure led by the wireless terminal 20, the wireless terminals 20 connecting to a specific radio base station 10 may be biased, and the utilization efficiency of the wireless resources of the entire wireless communication system may decrease.

[0019] FIG. 16 is a diagram for explaining the problems of the wireless communication system using blockchain. In the example of FIG. 16, the wireless communication system 1 includes a plurality of radio base stations 10a, 10b, 10c as an example for explanation. Note that the radio base stations may or may not include an indoor radio base station 10c.

[0020] In FIG. 16, it is assumed that the radio base station 10a forms a network cell 11a and can communicate with the radio terminals 20a, 20b, 20c, and 20f within the network cell 11a. The radio base station 10b forms a network cell 11b and can communicate with the radio terminals 20b and 20e within the network cell 11b. The radio base station 10c forms a network cell 11c and can communicate with the radio terminals 20c and 20d within the network cell 11c.

[0021] In this state, when each radio terminal 20 autonomously determines the connection destination radio base station, for example, as shown in FIG. 16, there may be a case where the radio terminals 20a, 20b, and 20c to be connected concentrate on a specific radio base station 10a. Further, when the radio terminal 20f starts new communication, for example, if it connects to a radio base station 10a that is closer, the utilization efficiency of the radio resources of the entire radio communication system 1 may further decrease.

[0022] Therefore, in this embodiment, a radio communication method and a radio communication system for improving the utilization efficiency of the radio resources of the entire radio communication system will be described.

[0023] <System Configuration> FIG. 1 is a diagram showing an example of the system configuration of a wireless communication system according to the present embodiment. As shown in FIG. 1, the wireless communication system 100 includes a plurality of radio base stations 110a, 110b, 110c, 110d, 110e,... that form different network cells. For example, the radio base station 110a forms a network cell 111a and can communicate with a wireless terminal 120b within the network cell 111a. The radio base station 110b forms a network cell 111b and can communicate with a wireless terminal 120a within the network cell 111b. Similarly, the radio base station 110c forms a network cell 111c and can communicate with wireless terminals 120b, 120c, 120d within the network cell 111c. Further, the radio base station 110d forms a network cell 111d, and the radio base station 110e forms a network cell 111e.

[0024] In the following description, when indicating an arbitrary radio base station among the radio base stations 110a, 110b, 110c, 110d, 110e,..., "radio base station 110" is used. Also, when indicating an arbitrary wireless terminal among the wireless terminals 120a, 120b, 120c, 120d, "wireless terminal 120" is used. The number of radio base stations 110 and the number of wireless terminals 120 shown in FIG. 1 are examples, and other numbers may be used.

[0025] The plurality of radio base stations 110 also function as nodes participating in the blockchain network 200, for example, as shown in FIG. 2, and the plurality of radio base stations 110 share the same blockchain. Here, the blockchain network 200 is a P2P (Peer-to-Peer) network (decentralized network) in which each node can send and receive data to and from other nodes equally without going through a server or the like. A blockchain is a distributed ledger in which a plurality of nodes participating in a P2P network record transactions between two parties or the like in a verifiable and permanent manner. Note that the blockchain network 30 may include nodes other than the radio base stations 110 (for example, other computers, wireless terminals, etc.).

[0026] Each radio base station 110 manages the connection with the radio terminal 120 by using a blockchain. For example, each radio base station 110 records and manages the transaction data 2 and the like described in FIG. 15 in a blockchain shared by a plurality of radio base stations 110. Thereby, the radio base station 110 can obtain information about other radio base stations 110 by referring to the blockchain.

[0027] (Overview of processing) Here, returning to FIG. 1, the overview of the processing of the wireless communication system 100 according to the present embodiment will be described.

[0028] Each radio base station 110 broadcasts the connection conditions for connecting to its own station to the radio terminals 120 within its own network cell 111. This connection condition includes information such as, for example, the communication quality to be provided and the connection cost (connection fee) for connecting to the radio base station 110.

[0029] The radio terminal 120 that starts communication receives the connection conditions transmitted by the surrounding radio base stations 110, and determines the radio base station 110 to which to request a connection based on the connection conditions. For example, among one or more radio base stations 110 that have received the connection conditions, the radio terminal 120 determines the radio base station 110 that satisfies the communication quality required by the radio terminal 120 and has the lowest connection cost as the radio base station 110 to which to request a connection.

[0030] However, only by this method, as in the wireless communication system 1 described in FIGS. 15 and 16, traffic may concentrate on a specific radio base station 110. For example, in FIG. 1, it is assumed that the radio terminal 120a is connected to the radio base station 110, and the radio terminals 120c and 120d are connected to the radio base station 110c.

[0031] In this state, when the wireless terminal 120b newly starts communication, in the conventional technology, it is difficult to control the wireless terminal 120b to connect to the wireless base station 110a with a lower congestion level in order to reduce the congestion level of the wireless base station 110c. For example, in the wireless communication method described with reference to FIGS. 15 and 16, the wireless terminal 120b in FIG. 1 cannot be preferentially connected to the wireless base station 110a with a lower congestion level.

[0032] In addition, it is not practical to control the optimal connection destination for all the wireless terminals 120 by the centralized control of the control station that manages the wireless communication system 1, because the processing amount becomes extremely large as the number of the wireless base stations 110 and the wireless terminals 120 increases.

[0033] Therefore, the wireless base station 110 according to the present embodiment has a function of calculating the normalized congestion level of other wireless base stations 110 by using the ledger information of the blockchain shared by the plurality of wireless base stations 110.

[0034] As an example, the wireless base station 110 acquires the maximum communication quality (for example, the maximum throughput) of other wireless base stations 110 and the number of wireless terminals accommodated by other wireless base stations 110 from the blockchain. Further, the wireless base station 110 normalizes the number of wireless terminals accommodated by other wireless base stations 110 according to the ratio between the maximum communication quality of its own station and the maximum communication quality of other wireless base stations 110, and calculates the normalized congestion level.

[0035] As another example, the wireless base station 110 acquires the average communication quality of other wireless base stations 110 and the number of wireless terminals accommodated by other wireless base stations 110 from the blockchain. Further, the wireless base station 110 may normalize the average communication quality of other wireless base stations 110 according to the ratio between the number of wireless terminals accommodated by its own station and the number of wireless terminals accommodated by other wireless base stations 110, and calculate the normalized congestion level.

[0036] In addition, the radio base station 110 has a function of controlling the connection cost of its own station based on the normalized congestion level of its own station and other radio base stations 110. For example, when the normalized congestion level of other radio base stations 110 is higher than that of its own station, the radio base station 110 reduces the connection cost of its own station. Or, when the normalized congestion level of other radio base stations 110 is lower than that of its own station, the radio base station 110 increases the connection cost of its own station.

[0037] Thereby, the wireless communication system 100 according to the present embodiment can be controlled, for example, in FIG. 1, so that the wireless terminal 120b that newly starts communication preferentially selects the radio base station 110a with a lower connection cost than the radio base station 110c as the connection destination.

[0038] Note that, instead of the normalized congestion level, a method of controlling the connection cost of its own station based on, for example, the number of wireless terminals accommodated by its own station and other radio base stations 110 is also conceivable. However, in this method, since the difference in performance (communication quality) of each radio base station 110 cannot be considered, there are problems such as a decrease in the utilization efficiency of the radio base station 110 with high communication quality, or a difference in the communication quality of the wireless terminal 120.

[0039] On the other hand, in the wireless communication system 100 according to the present embodiment, since the connection cost of its own station is controlled based on the normalized congestion level, it is possible to suppress a decrease in the utilization efficiency of the radio base station 110 with high communication quality and smooth the communication quality of the wireless terminal 120.

[0040] <Functional Configuration> Subsequently, the functional configurations of the radio base station 110 and the wireless terminal 120 according to the present embodiment will be described.

[0041] (Functional Configuration of Radio Base Station) FIG. 3 is a diagram showing an example of the functional configuration of the radio base station according to the present embodiment. The radio base station 110 includes, for example, a computer configuration, and when the computer executes a predetermined program, a radio communication unit 301, a transmission unit 302, a management unit 303, a calculation unit 304, a modification unit 305, a storage unit 306, a wired communication unit 307, etc. are realized. Note that at least a part of each of the above functional configurations may be realized by hardware.

[0042] The radio communication unit 301 forms a network cell 111 capable of radio communication with the radio base station 110, and executes radio communication processing for performing radio communication with the radio terminal 120 connected to the radio base station 110.

[0043] The transmission unit 302 executes a transmission process of broadcasting the connection conditions for connecting to the radio base station 110 to the radio terminal 120 within the network cell 111 of the radio base station 110. This connection condition includes, for example, information such as the communication quality provided by the radio base station 110 and the connection cost (connection fee) for connecting to the radio base station 110.

[0044] The management unit 303 executes a management process of managing the information of the radio terminal 120 connected to the radio base station 110 based on the connection conditions transmitted by the transmission unit 302 using a blockchain shared by a plurality of radio base stations 110. For example, the management unit 303 executes a series of processes described in steps S1 to S6 of FIG. 15 with the radio terminal 120 that requests connection to the radio base station 110, and records the connection information with the radio terminal 120 in the blockchain 320 shared with other radio base stations 110.

[0045] In addition, the management unit 303 executes various processes for managing the blockchain as a node of the blockchain shared by a plurality of radio base stations 110. By executing the same processes in other radio base stations 110 as well, information on the wireless terminals 120 connected to each radio base station 110 within the wireless communication system 100 is recorded in the blockchain 320. Therefore, by referring to the blockchain 320, the radio base station 110 can obtain information such as the information on the wireless terminals 120 connected to other radio base stations 110, the communication quality of the wireless communication network provided by other radio base stations 110, and the connection cost.

[0046] The calculation unit 304 executes a calculation process for calculating the normalized congestion degree of other radio base stations 110 using the ledger information of the blockchain 320. Specific processing details of the calculation process executed by the calculation unit 304 will be described later by exemplifying a plurality of embodiments.

[0047] The change unit 305 changes the connection conditions of the radio base station 110 based on the normalized congestion degree calculated by the calculation unit 304. For example, when the local station (radio base station 110) is congested, the change unit 305 increases the connection cost of the local station. Also, when the local station is not congested, the change unit 305 decreases the connection cost of the local station.

[0048] Here, the connection cost is the cost (e.g., connection fee) for the wireless terminal 120 to connect to the radio base station 110. The wireless terminal 120 preferentially connects to the radio base station 110 with the lowest connection cost among the radio base stations 110 that satisfy the required communication quality, for example.

[0049] Note that when the distance between the radio base station 110 and the wireless terminal 120 is short, the transmission power can be reduced, and when the communication speed between the radio base stations 110 and 120 is high, the communication time can be shortened. Therefore, in addition to the connection cost, the wireless terminal 120 may determine the radio base station 110 to connect to taking into account the received signal strength or communication speed from the radio base station 110.

[0050] Note that the transmission unit 302, the management unit 303, the calculation unit 304, the change unit 305, etc. are included in, for example, a communication control unit 310 that controls wireless communication by the wireless communication unit 301.

[0051] The storage unit 306 executes storage processing for storing various data, information, programs, etc. including the blockchain 320 in, for example, a storage device provided in the wireless base station 110.

[0052] The wired communication unit 307 connects the wireless base station 110 to, for example, a wired communication network and executes communication related to the blockchain network 200 as shown in, for example, FIG. 2.

[0053] (Functional Configuration of Wireless Terminal) FIG. 4 is a diagram showing an example of the functional configuration of the wireless terminal according to the present embodiment. The wireless terminal 120 has, for example, a computer configuration, and by executing a predetermined program by the computer, a wireless communication unit 401, a reception unit 402, a determination unit 403, a connection control unit 404, a storage unit 405, etc. are realized. Note that at least a part of each of the above functional configurations may be realized by hardware.

[0054] The wireless communication unit 401 executes wireless communication processing for connecting to the wireless base station 110 by wireless communication and transmitting and receiving data. The reception unit 402 executes reception processing for receiving connection conditions transmitted by the wireless base station 110 using the wireless communication unit 401.

[0055] The determination unit 403 determines the radio base station 110 to which the wireless terminal 120 requests connection based on the connection conditions received by the reception unit 402. For example, the wireless terminal 120 preferentially connects to the radio base station 110 with the lowest connection cost among the radio base stations 110 that satisfy the required communication quality. Note that when the distance between the wireless terminal 120 and the radio base station 110 is short, the transmission power can be reduced, and when the communication speed between the radio base station 110 and the wireless terminal 120 is high, the communication time can be shortened. Therefore, it is desirable for the wireless terminal 120 to determine the destination radio base station 110 based on the communication quality of the radio base station 110 and the connection cost.

[0056] The connection control unit 404 executes a connection process to connect to the destination radio base station 110 determined by the determination unit 403. For example, in the connection process described in step S1 of FIG. 15, the connection control unit 404 transmits a connection request to the destination radio base station 110 and reaches an agreement regarding the provided wireless communication service.

[0057] Note that the reception unit 402, the determination unit 403, the connection control unit 404, etc. are included in a communication control unit 410 that controls wireless communication by, for example, the wireless communication unit 401.

[0058] The storage unit 405 executes a storage process of storing various data, information, programs, etc. necessary for wireless communication in, for example, a storage device included in the wireless terminal 120.

[0059] <Flow of processing> Subsequently, the flow of processing of the wireless communication method according to the present embodiment will be described by exemplifying a plurality of examples.

[0060] (Processing of radio base station) FIG. 5 is a flowchart showing an example of the processing of the radio base station according to the present embodiment. This processing shows the overall flow of the processing executed by the radio base station 110 described in FIG. 3.

[0061] In step S501, the calculation unit 304 of the radio base station 110 identifies one or more other radio base stations 110 to which the radio terminal 120 may transition to the local station (radio base station 110).

[0062] In step S502, the calculation unit 304 calculates the normalized congestion degree of one or more other radio base stations 110 identified in step S501 using the ledger information of the blockchain 320. Here, as an example, the normalized congestion degree can be the number of wireless terminals (normalized wireless terminal number) obtained by normalizing the number of wireless terminals accommodated by other radio base stations 110 by the ratio of the maximum communication quality of the radio base station 110 to the maximum communication quality of other radio base stations. As another example, the normalized congestion degree can be the communication quality (normalized communication quality) obtained by normalizing the average communication quality of other radio base stations 110 by the ratio of the number of wireless terminals accommodated by the radio base station 110 to the number of wireless terminals accommodated by other radio base stations 110. Note that the calculation methods of the normalized wireless terminal number and the normalized communication quality will be described later.

[0063] In step S503, the change unit 305 changes the connection condition of the local station (radio base station 110) based on the normalized congestion degree calculated by the calculation unit 304. For example, when the local station is more congested than other radio base stations 110, the change unit 305 increases the connection cost of the local station. When there are multiple other radio base stations 110, the change unit 305 may determine that the local station is more congested than other radio base stations 110 if the number of other radio base stations 110 that are more congested than the local station is greater than the number of other radio base stations 110 that are less congested than the local station.

[0064] Also, when the local station is less congested than other radio base stations 110, the change unit 305 decreases the connection cost of the local station. When there are multiple other radio base stations 110, the change unit 305 may determine that the local station is less congested than other radio base stations 110 if the number of other radio base stations 110 that are more congested than the local station is less than the number of other radio base stations 110 that are less congested than the local station.

[0065] In step S504, the transmission unit 302 broadcasts the connection conditions using the wireless communication unit 301. For example, the transmission unit 302 periodically transmits a notification message including the connection conditions, such as information on the communication quality and connection cost of the wireless communication provided by the local station (wireless base station 110), via wireless communication.

[0066] In step S505, the management unit 303 determines whether the wireless communication unit 301 has received a connection request from the wireless terminal 120. If a connection request is received, the processes after step S506 are executed.

[0067] When moving to step S506, the management unit 303 uses the blockchain 320 to execute the connection process described in steps S1 to S6 of FIG. 15, for example.

[0068] In step S507, the management unit 303 determines whether a connection contract with the wireless terminal 120 has been established. If the connection contract has been established, the process is moved to step S508. On the other hand, if the connection contract has not been established, the management unit 303 returns the process to step S504.

[0069] When moving to step S508, the wireless base station 110 starts communication with the wireless terminal 120 that sent the connection request and returns the process to step S504. Also, in step S509, when the communication is completed, the wireless base station 110 returns the process to step S504.

[0070] Note that the calculation unit 304 executes the process of step S510, for example, in parallel with the processes of steps S507 to S511.

[0071] In step S510, the calculation unit 304 determines whether a predetermined time has elapsed since the processing 500 in steps S501 to S503 was last executed. Here, the predetermined time is the preset update interval of the connection cost. If the predetermined time has elapsed, the calculation unit 304 executes the processing 500 in steps S501 to S503 again. If the predetermined time has not elapsed, the calculation unit 304 returns the processing to step S504 and waits until the predetermined time elapses.

[0072] By the above processing, the radio base station 110 can change the connection conditions of the radio base station 110 based on the normalized congestion level of other surrounding radio base stations 110. Also, by each of the plurality of radio base stations 110 included in the radio communication system 100 executing the processing in FIG. 5, the utilization efficiency of the radio resources of the entire radio communication system 100 can be improved.

[0073] (Processing of wireless terminal) FIG. 6 is a flowchart showing the flow of processing of the wireless terminal according to the present embodiment. This processing shows an example of processing executed when the wireless terminal 120 described in FIG. 4 starts wireless communication.

[0074] In step S601, the receiving unit 402 receives the connection conditions broadcast by the radio base station 110. As described above, this connection condition includes information such as the communication quality of the wireless communication provided by the radio base station 110 and the connection cost.

[0075] In step S602, the determination unit 403 determines the radio base station 110 to which the wireless terminal 120 requests connection based on the connection conditions received by the receiving unit 402. For example, the determination unit 403 may determine, as the radio base station 110 to which connection is requested, the radio base station 110 with the lowest connection cost among the radio base stations 110 that satisfy the required communication quality. Also, when there are a plurality of radio base stations 110 with equal connection costs, the determination unit 403 may determine, as the radio base station 110 to which connection is requested, the radio base station 110 with the highest communication quality.

[0076] In step S603, the connection control unit 404 transmits a connection request for requesting a wireless communication connection to the radio base station 110 determined by the determination unit 403. The radio base station 110 that has received this connection request executes the process of step S506 in FIG. 5.

[0077] In step S604, the connection control unit 404 determines whether a connection contract with the radio base station 110 has been established. If the connection contract has been established, the process proceeds to step S605. On the other hand, if the connection contract has not been established, the wireless terminal 120 ends the process of FIG. 6.

[0078] When the process proceeds to step S605, the wireless terminal 120 starts communicating with the connected radio base station 110. In step S606, when the communication is completed, the process of FIG. 6 ends.

[0079] Through the above process, the wireless terminal 120 can preferentially connect to the radio base station 110 with a lower connection cost among the surrounding radio base stations 110.

[0080] Note that if the communication quality deteriorates during communication, the wireless terminal 120 may execute the process of FIG. 6 again and switch the connection destination to a new radio base station 110. Also, if the connection cost of the radio base station 110 increases during communication, the wireless terminal 120 may execute the process of FIG. 6 again and switch the connection destination to a new radio base station 110.

[0081] <Connection condition change process> Subsequently, a specific example will be illustrated and described for the connection condition change process executed by the radio base station 110.

[0082] [Example 1] (Functional configuration of the calculation unit) FIG. 7 is a diagram showing an example of the functional configuration of the calculation unit according to Example 1. The calculation unit 304 includes, for example, a specifying unit 701, an information acquisition unit 702, a normalization unit 703, and the like.

[0083] The specific unit 701 executes a specific process for identifying one or more other radio base stations 110 to which the wireless terminal 120 may transition to the local station (radio base station 110). For example, the specific unit 701 obtains, from the blockchain 320, the transition information of the radio base station 110 to which the wireless terminal 120 is connected, and identifies other radio base stations 110 to which the wireless terminal 120 has transitioned to the local station.

[0084] As a specific example, in FIG. 1, the specific unit 701 of the radio base station 110a determines, from the blockchain 320, whether there is a history that the wireless terminal 120 has connected to the radio base station 110a after connecting to the radio base station 110b. If there is such a history, the specific unit 701 of the radio base station 110a determines the radio base station 110b as a radio base station 110 to which the wireless terminal 120 may transition to the local station. By also executing the same process for other radio base stations 110c, 110d, 110e, ···, the specific unit 701 of the radio base station 110a can identify other radio base stations 110b, 110c adjacent or close to the radio base station 110a.

[0085] The information acquisition unit 702 obtains, from the blockchain 320, the maximum communication quality of the other radio base stations 110 identified by the specific unit 701 and the number of wireless terminals 120 accommodated by the other radio base stations 110 (hereinafter referred to as the terminal accommodation number). The maximum communication quality of the other radio base stations 110 can be, for example, the maximum value of the throughput of the wireless communication provided by the other radio base stations 110. Also, the terminal accommodation number of the other radio base stations 110 is, for example, the number of wireless terminals 120 currently connected to the other radio base stations 110.

[0086] The normalization unit 703 calculates a normalized terminal accommodation number obtained by normalizing the terminal accommodation number of the other radio base stations 110, for example, based on the ratio between the maximum communication quality of the local station (radio base station 110) and the maximum communication quality of the other radio base stations 110. For example, the normalization unit 703 calculates the normalized terminal accommodation number according to the following (Equation 1).

[0087]

Equation

[0088] (Connection condition change process) FIG. 8 is a flowchart showing an example of the connection condition change process according to the first embodiment. This process shows a specific example of process 500 in steps S501 to S503 in FIG. 5, for example.

[0089] In step S801, the specifying unit 701 specifies one or more other radio base stations 110 to which the radio terminal 120 may transition in the local station (radio base station 110).

[0090] In step S802, the information acquisition unit 702 acquires, from the blockchain 320, the maximum communication quality and the terminal accommodation number of one or more other radio base stations 110 specified by the specifying unit 701.

[0091] In step S803, the normalization unit 703 applies the maximum communication quality and the terminal accommodation number of one or more other radio base stations 110 acquired by the information acquisition unit 702 to formula (1) to calculate the normalized terminal accommodation number of one or more other radio base stations 110.

[0092] In step S804, the change unit 305 determines whether the local station is congested. For example, when the terminal accommodation number of the local station (= normalized terminal accommodation number) is larger than the normalized terminal accommodation number of other radio base stations 110, the change unit 305 determines that the local station is congested. Also, when there are a plurality of other radio base stations 110, the change unit 305 determines that the local station is congested when the number of other radio base stations 110 with a normalized terminal accommodation number larger than the terminal accommodation number of the local station is larger than the number of other radio base stations 110 with a normalized terminal accommodation number smaller than the terminal accommodation number of the local station.

[0093] When the local station is congested, the change unit 305 causes the process to shift to step S805 and increases the connection cost of the local station. On the other hand, when the local station is not congested, the change unit 305 causes the process to shift to step S806 and decreases the connection cost of the local station.

[0094] Note that the processes of steps S805 and S806 in FIG. 8 are merely examples. For example, when increasing the connection cost of the local station in step S805, the change unit 305 may set the connection cost of the local station to a default value in step S806. Also, when decreasing the connection cost of the local station in step S806, the change unit 305 may set the connection cost of the local station to a default value in step S805.

[0095] FIG. 9 is a diagram showing a specific example of the connection condition change process according to the first embodiment. In FIG. 9, the “local station” is, for example, the radio base station 110a in FIG. 1, with a maximum T (maximum throughput) of 100 Mbps and a terminal accommodation number of 10. Also, in FIG. 9, “BS1” is, for example, the radio base station 110b in FIG. 1, with a maximum T of 200 Mbps and a terminal accommodation number of 10. Similarly, “BS2” is, for example, the radio base station 110c in FIG. 1, with a maximum T of 300 Mbps and a terminal accommodation number of 10.

[0096] In this case, the calculation unit 304 of the local station applies the maximum T (an example of the maximum communication quality) of the local station “100 Mbps”, the maximum T of BS1 “200 Mbps”, and the terminal accommodation number of BS1 “10” to (Equation 1) to calculate the normalized terminal accommodation number of BS1 “5”. Similarly, the calculation unit 304 of the local station applies the maximum T (an example of the maximum communication quality) of the local station “100 Mbps”, the maximum T of BS1 “300 Mbps”, and the terminal accommodation number of BS2 “10” to (Equation 1) to calculate the normalized terminal accommodation number of BS2 “3.3”.

[0097] The self-station change unit 305 compares the number of terminals accommodated at the self-station (= normalized number of accommodated terminals) "10" with the normalized number of accommodated terminals of BS1 "5" and the normalized number of accommodated terminals of BS2 "3.3", determines that the self-station is relatively congested, and increases the connection cost of the self-station. Note that as the increase or decrease range of the connection cost of the self-station, a fixed value may be used, or the increase or decrease range may be set larger as the difference between the normalized number of accommodated terminals of the self-station and another radio base station (for example, BS1) is larger.

[0098] Note that the normalized terminal accommodation number is an example of the normalized congestion degree calculated by the calculation unit 304. In this way, the radio base station 110 can use the normalized terminal accommodation number as the normalized congestion degree.

[0099] [Example 2] (Functional configuration) The functional configuration of the calculation unit 304 according to Example 2 is the same as the functional configuration of the calculation unit 304 according to Example 1 shown in FIG. 7. However, since the processing contents of the information acquisition unit 702 and the normalization unit 703 are partially different, the differences from Example 1 will be described here.

[0100] The information acquisition unit 702 acquires from the blockchain 320 the average communication quality of another radio base station 110 specified by the specifying unit 701 and the number of terminals accommodated by the other radio base station 110. As the average communication quality of another radio base station 110, for example, the average value (average T) of the throughput of the wireless communication provided by the other radio base station 110 can be applied.

[0101] The normalization unit 703 calculates a normalized communication quality obtained by normalizing the average communication quality of another radio base station 110, for example, by the ratio between the number of terminals accommodated by the self-station (radio base station 110) and the number of terminals accommodated by another radio base station 110. For example, the normalization unit 703 calculates the normalized communication quality according to the following (Equation 2).

[0102] [Equation] Here, U my_BSis the number of terminals accommodated by the local station (radio base station 110), U shift_BSi is the number of terminals accommodated by other radio base stations 110, T i is the average communication quality of other radio base stations 110.

[0103] (Connection condition change process) Figure 10 is a flowchart showing an example of the connection condition change process according to the second embodiment. This process shows, for example, a specific example of process 500 in steps S501 to S503 of FIG. 5. Among the processes shown in FIG. 10, the processes in steps S801, S805, and S806 are the same as those of the first embodiment described in FIG. 8, and thus the description thereof is omitted here.

[0104] In step S1001, the information acquisition unit 702 acquires, from the blockchain 320, the average communication quality and the number of terminals accommodated by one or more other radio base stations 110 specified by the specifying unit 701.

[0105] In step S1002, the normalization unit 703 applies the average communication quality and the number of terminals accommodated by one or more other radio base stations 110 acquired by the information acquisition unit 702 to (Equation 2) to calculate the normalized communication quality of one or more other radio base stations 110.

[0106] In step S1003, the change unit 305 determines whether the local station is congested. For example, if the average communication quality (= normalized communication quality) of the local station is worse than the normalized communication quality of other radio base stations 110, the change unit 305 determines that the local station is congested. Further, when there are a plurality of other radio base stations 110, the change unit 305 determines that the local station is congested when the number of other radio base stations 110 with better normalized communication quality than the average communication quality of the local station is greater than the number of other radio base stations 110 with worse normalized communication quality than the average communication quality of the local station.

[0107] When the local station is congested, the change unit 305 shifts the process to step S805 to increase the connection cost of the local station. On the other hand, when the local station is not congested, the change unit 305 shifts the process to step S806 to decrease the connection cost of the local station.

[0108] FIG. 11 is a diagram showing a specific example of the connection condition change process according to the second embodiment. In FIG. 11, the "local station" is, for example, the radio base station 110a in FIG. 1, and it is assumed that the average T (average throughput) is 100 Mbps and the number of accommodated terminals is 10. Also, in FIG. 11, "BS1" is, for example, the radio base station 110b in FIG. 1, and it is assumed that the average T is 200 Mbps and the number of accommodated terminals is 10. Similarly, "BS2" is, for example, the radio base station 110c in FIG. 1, and it is assumed that the average T is 300 Mbps and the number of accommodated terminals is 10.

[0109] In this case, the calculation unit 304 of the local station applies the number of accommodated terminals "10" of the local station, the number of accommodated terminals "10" of BS1, and the average T "200 Mbps" of BS1 to (Equation 2) to calculate the normalized communication quality (normalized T) "200" of BS1. Similarly, the calculation unit 304 of the local station applies the number of accommodated terminals "10" of the local station, the number of accommodated terminals "10" of BS2, and the average T "300 Mbps" of BS2 to (Equation 2) to calculate the normalized communication quality "300" of BS2.

[0110] The change unit 305 of the local station compares the average communication quality (= normalized communication quality) "100" of the local station, the normalized communication quality "200" of BS1, and the normalized communication quality "300" of BS2, and determines that the local station is relatively congested, and increases the connection cost of the local station. Note that, as the increase or decrease range of the connection cost of the local station, a fixed value may be used, or the increase or decrease range may be set larger as the difference in the normalized communication quality between the local station and another radio base station (for example, BS1) is larger.

[0111] Note that the normalized communication quality is an example of the normalized congestion degree calculated by the calculation unit 304. In this way, the radio base station 110 may use the normalized communication quality as the normalized congestion degree.

[0112] <Hardware Configuration Example> FIG. 12 is a diagram showing an example of the hardware configuration of a radio base station and a radio terminal according to the present embodiment. The radio base station 110 and the radio terminal 120 are configured, for example, as a computer 1200 as shown in FIG. 12. In the example of FIG. 12, the computer 1200 includes a processor 1201, a memory 1202, a storage device 1203, a communication device 1204, an input device 1205, an output device 1206, a bus B, and the like.

[0113] The processor 1201 is an arithmetic device such as a CPU (Central Processing Unit) that realizes various functions by executing a predetermined program, for example. The memory 1202 is a storage medium readable by the computer 1200 and includes, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The storage device 1203 is a computer-readable storage medium and may include, for example, an HDD (Hard Disk Drive), an SSD (Solid State Drive), various optical disks, and magneto-optical disks.

[0114] The communication device 1204 includes one or more hardware (communication devices) for communicating with other devices via a wireless or wired network. For example, the communication device 1204 of the computer 1200 included in the radio base station 110 includes a communication device for wireless communication and a communication device for wired communication. Further, the communication device 1204 of the computer 1200 included in the radio terminal 120 includes a communication device for wireless communication.

[0115] The input device 1205 is an input device that receives external input (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.). The output device 1206 is an output device that performs external output (for example, a display, a speaker, an LED lamp, etc.). Note that the input device 1205 and the output device 1206 may be integrated (for example, an input / output device such as a touch panel display).

[0116] Bus B is commonly connected to each of the above components and transmits, for example, address signals, data signals, and various control signals. Note that the processor 1201 is not limited to a CPU and may be, for example, a DSP (Digital Signal Processor), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

[0117] (Supplementary note) The radio base station 110 and the radio terminal 120 in this embodiment are not limited to being realized by dedicated devices and may be realized by a general-purpose computer. In that case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to realize it. Here, the "computer system" is assumed to include hardware such as an OS and peripheral devices.

[0118] Also, the "computer-readable recording medium" includes various storage devices such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and other portable media, and hard disks built into a computer system. Furthermore, the "computer-readable recording medium" includes, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, something that dynamically holds a program for a short time, and also includes something that holds a program for a certain time, like a volatile memory inside a computer system that serves as a server or a client in that case.

[0119] Also, the above program may be for realizing a part of the aforementioned functions, and may also be for realizing a combination of the aforementioned functions with a program already recorded in a computer system, and may be realized using hardware such as a PLD (Programmable Logic Device) or an FPGA (Field Programmable Gate Array).

[0120] <Effect of the Embodiment> The effect of the wireless communication method according to this embodiment was confirmed using a computer simulator. As calculation conditions, a wireless LAN (Local Area Network) base station and a local 5G (5th Generation) base station as shown in Table 1301 of FIG. 13 were arranged in an area 1302 as shown in FIG. 13, and the congestion situation at the center of the area 1302 was simulated.

[0121] The simulation results of the cumulative distribution function (CDF: Cumulative Distribution Function) of the throughput for each wireless terminal 120 of "Example 1", "Comparative Example 1", and "Comparative Example 2" are shown in the graph 1401 of FIG. 14. Also, the median values of the throughput of "Example 1", "Comparative Example 1", and "Comparative Example 2" are shown in Table 1402 of FIG. 14.

[0122] Here, "Example 1" shows the simulation results when each wireless base station dispersively controls the connection cost using the normalized terminal accommodation number, as described with reference to FIGS. 7 to 9. "Comparative Example 1" shows the simulation results of the prior art in which each wireless base station does not control the connection cost and keeps the connection cost constant. "Comparative Example 2" shows the simulation results when each wireless base station dispersively controls the connection cost using the non-normalized terminal accommodation number.

[0123] According to Table 1402, when each wireless base station dispersively controls the connection cost using the non-normalized terminal accommodation number as in "Comparative Example 2", an effect of improving the median value of the throughput by about 1.6 times can be expected compared to the prior art as in "Comparative Example 1". Furthermore, when the terminal accommodation number is normalized and each wireless base station dispersively controls the connection cost as in "Example 1", an effect of improving the median value of the throughput by 1.4 times can be expected compared to "Comparative Example 2".

[0124] As described above, according to this embodiment, the utilization efficiency of radio resources of the entire wireless communication system can be improved. Further, in the wireless communication system 100 according to this embodiment, based on the normalized congestion degree, the connection cost of the local station is controlled, so that the decrease in the utilization efficiency of the radio base station 110 with high communication quality is suppressed, and the communication quality of the wireless terminal 120 can be smoothed.

[0125] <Summary of the Embodiment> This specification discloses at least the wireless communication methods and wireless communication systems of the following respective items. (Item 1) A radio base station a transmission process of broadcasting the connection conditions of the radio base station; a management process of managing the connection with a wireless terminal that requests connection to the radio base station based on the connection conditions using a blockchain shared by a plurality of radio base stations; a calculation process of calculating the normalized congestion degree of other radio base stations using the ledger information of the blockchain; a change process of changing the connection conditions of the radio base station based on the normalized congestion degree; A wireless communication method for executing the above. (Item 2) The calculation process obtains the maximum communication quality of the other radio base stations and the number of wireless terminals accommodated by the other radio base stations from the blockchain; sets the normalized number of terminals accommodated, which is obtained by normalizing the number of wireless terminals accommodated by the other radio base stations by the ratio of the maximum communication quality of the radio base station to the maximum communication quality of the other radio base stations, as the normalized congestion degree; The wireless communication method according to Item 1. (Item 3) The calculation process obtains the average communication quality of the other radio base stations and the number of wireless terminals accommodated by the other radio base stations from the blockchain; The normalized communication quality obtained by normalizing the average communication quality of the other radio base station based on the ratio between the number of radio terminals accommodated by the radio base station and the number of radio terminals accommodated by the other radio base station is defined as the normalized congestion level. The wireless communication method according to claim 1. (Item 4) In the change process, when the normalized congestion level of the other radio base station is higher than that of the radio base station, the connection cost of the radio base station is reduced. The wireless communication method according to any one of Items 1 to 3. (Item 5) In the change process, when the normalized congestion level of the other radio base station is lower than that of the radio base station, the connection cost of the radio base station is increased. The wireless communication method according to any one of Items 1 to 3. (Item 6) The other radio base station includes one or more radio base stations among the plurality of radio base stations to which radio terminals may transition from the radio base station. The wireless communication method according to any one of Items 1 to 3. (Item 7) The other radio base station includes one or more radio base stations adjacent to or close to the radio base station. The wireless communication method according to any one of Items 1 to 3. (Item 8) A wireless communication system including a plurality of radio base stations and radio terminals, The radio base station includes A transmission unit that broadcasts the connection conditions of the radio base station, A management unit that manages the connection between the radio terminal that requests connection to the radio base station based on the connection conditions using a blockchain shared by the plurality of radio base stations, A calculation unit that calculates the normalized congestion level of other radio base stations using the ledger information of the blockchain, A change unit that changes the connection conditions of the radio base station based on the normalized congestion level, and has The radio terminal includes A receiving unit that receives the connection conditions, A determination unit that determines the radio base station to which the radio terminal requests connection based on the connection condition; having a radio communication system.

[0126] As described above, this embodiment has been explained, but the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

Explanation of symbols

[0127] 100 Radio communication system 110, 110a to 110e Radio base stations 120, 120a to 120d Radio terminals 302 Transmission unit 303 Management unit 304 Calculation unit 305 Change unit 306 Storage unit 320 Blockchain 402 Reception unit 403 Determination unit

Claims

1. A wireless base station, a transmission process for broadcasting the connection conditions of the wireless base station, a management process for managing, using a blockchain shared by a plurality of wireless base stations, the connection with a wireless terminal that requests connection to the wireless base station based on the connection conditions, a calculation process for calculating, using the ledger information of the blockchain, the normalized congestion degree of other wireless base stations, a change process for changing the connection conditions of the wireless base station based on the normalized congestion degree, A wireless communication method for executing the above.

2. The calculation process obtains, from the blockchain, the maximum communication quality of the other wireless base stations and the number of wireless terminals accommodated by the other wireless base stations, and sets, as the normalized congestion degree, the normalized number of terminals accommodated, which is obtained by normalizing the number of wireless terminals accommodated by the other wireless base stations by the ratio of the maximum communication quality of the wireless base station to the maximum communication quality of the other wireless base stations. The wireless communication method according to claim 1.

3. The calculation process obtains, from the blockchain, the average communication quality of the other wireless base stations and the number of wireless terminals accommodated by the other wireless base stations, and sets, as the normalized congestion degree, the normalized communication quality, which is obtained by normalizing the average communication quality of the other wireless base stations by the ratio of the number of wireless terminals accommodated by the wireless base station to the number of wireless terminals accommodated by the other wireless base stations. The wireless communication method according to claim 1.

4. The change process reduces the connection cost of the wireless base station when the normalized congestion degree of the other wireless base stations is higher than that of the wireless base station. The wireless communication method according to any one of claims 1 to 3.

5. The change process increases the connection cost of the wireless base station when the normalized congestion degree of the other wireless base stations is lower than that of the wireless base station. The wireless communication method according to any one of claims 1 to 3.

6. The other wireless base stations include one or more wireless base stations among the plurality of wireless base stations to which a wireless terminal may transition from the wireless base station. The wireless communication method according to any one of claims 1 to 3.

7. The other wireless base stations include one or more wireless base stations adjacent or close to the wireless base station. The wireless communication method according to any one of claims 1 to 3.

8. A wireless communication system including a plurality of wireless base stations and a wireless terminal, wherein the wireless base station A transmission unit that broadcasts connection conditions of the wireless base station; A management unit that manages, using a blockchain shared by the plurality of wireless base stations, a connection with a wireless terminal that requests connection to the wireless base station based on the connection conditions; A calculation unit that calculates a normalized congestion level of other wireless base stations using ledger information of the blockchain; A change unit that changes the connection conditions of the wireless base station based on the normalized congestion level; comprising; The wireless terminal; A reception unit that receives the connection conditions; A determination unit that determines, based on the connection conditions, the wireless base station to which the wireless terminal requests connection; comprising; A wireless communication system.

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