WO2024069761A1

WO2024069761A1 - Wireless communication system, centralized station, wireless communication method, and centralized control program

Info

Publication number: WO2024069761A1
Application number: PCT/JP2022/035966
Authority: WO
Inventors: 隼人福園; 利文宮城; 武鬼沢; 達樹奥山; 聡須山; 祥久岸山
Original assignee: 日本電信電話株式会社; 株式会社Ｎｔｔドコモ
Priority date: 2022-09-27
Filing date: 2022-09-27
Publication date: 2024-04-04

Abstract

A wireless communication system according to one embodiment of the present invention predicts, on the basis of a relevance degree of each user who uses a terminal, a traffic between the each terminal and each base station, selects a base station to connect on the basis of the traffic of each terminal, continuously collects the terminal position information relating to each terminal and a propagation loss information between each terminal and each base station, calculates a packet error rate of each selected base station on the basis of the collected terminal position information and propagation loss information, determines, on the basis of the calculated packet error rates, whether or not there is a terminal having a communication quality with respect to the base station less than a predetermined value, and when it is determined that there is a terminal having the communication quality less than the predetermined value, changes the base station to which the terminal is connected such that the communication quality of the connection of each terminal to the base station exceeds the predetermined value.

Description

Wireless communication system, central station, wireless communication method, and centralized control program

The present invention relates to a wireless communication system, a central station, a wireless communication method, and a central control program.

Technology has been studied for the past to efficiently communicate information by applying an algorithm similar to PageRank to the relevance of each user in a social networking service (SNS) and utilizing graph theory and big data analysis (see, for example, non-patent document 1).

For example, it is being considered to predict traffic at each base station (which exists in cyberspace) of a CPS (cyber physical system), feed that prediction back into the real world, and use it as a guide for base station selection for each user terminal.

In addition, methods are being considered for improving the efficiency of power used in wireless communication systems, for example, by using energy harvesting technology (see, for example, non-patent document 2).

However, in the past, the actual wireless conditions of each terminal were not reflected, and the accuracy of the base station that each terminal selected to connect to was low, which sometimes meant that the specified communication quality could not be achieved.

The present invention has been made in consideration of the above-mentioned problems, and aims to provide a wireless communication system, a central station, a wireless communication method, and a centralized control program that enable optimal selection of a base station to which each terminal should connect from among multiple base stations while maintaining a predetermined communication quality.

In one embodiment of the present invention, a wireless communication system includes a plurality of central stations that cooperate to centrally control a plurality of base stations each capable of accommodating a plurality of terminals. The central station includes a selection unit that predicts traffic between each of the terminals and each of the base stations based on the relevance of each of the users using the terminals, and selects the base station to which the terminals should connect based on the traffic of each of the terminals. A collection unit that continuously collects terminal location information indicating the location of each of the terminals and propagation loss information indicating the propagation loss between each of the terminals and each of the base stations. A calculation unit that calculates a packet error rate for each of the base stations selected by the selection unit based on the terminal location information and propagation loss information continuously collected by the collection unit. A determination unit that determines whether or not there is a terminal whose communication quality with respect to the base station is below a predetermined value based on the packet error rate calculated by the calculation unit. When the determination unit determines that there is a terminal whose communication quality with respect to the base station is below a predetermined value, a change unit that changes the base station to which the terminals connect so that the communication quality of each of the terminals connected to the base station exceeds the predetermined value.

In addition, a central station according to one embodiment of the present invention is a central station that centrally controls a plurality of base stations each capable of accommodating a plurality of terminals in cooperation with each other, and includes a selection unit that predicts traffic between each of the terminals and each of the base stations based on the relevance of each of the users using the terminals, and selects the base station to which the terminals should be connected based on the traffic of each of the terminals; a collection unit that continuously collects terminal location information indicating the location of each of the terminals and propagation loss information indicating the propagation loss between each of the terminals and each of the base stations; a calculation unit that calculates a packet error rate for each of the base stations selected by the selection unit based on the terminal location information and propagation loss information continuously collected by the collection unit; a determination unit that determines whether or not there is a terminal whose communication quality with respect to the base station is below a predetermined value based on the packet error rate calculated by the calculation unit; and a change unit that changes the base station to which the terminals are connected, when the determination unit determines that there is a terminal whose communication quality with respect to the base station is below a predetermined value, so that the communication quality with which each of the terminals connects to the base station exceeds the predetermined value.

In addition, a wireless communication method according to one embodiment of the present invention is a wireless communication method in which multiple central stations cooperate to centrally control multiple base stations each capable of accommodating multiple terminals, the method comprising: a selection step of predicting traffic between each of the terminals and each of the base stations based on the relevance of each of the users using the terminals, and selecting the base station to which the terminals should be connected based on the traffic of each of the terminals; a collection step of continuously collecting terminal location information indicating the location of each of the terminals and propagation loss information indicating the propagation loss between each of the terminals and each of the base stations; a calculation step of calculating a packet error rate for each of the base stations selected by the selection step based on the terminal location information and propagation loss information continuously collected by the collection step; a determination step of determining whether or not there is a terminal whose communication quality with respect to the base station is below a predetermined value based on the packet error rate calculated by the calculation step; and a change step of changing the base station to which the terminals are connected, when it is determined by the determination step that there is a terminal whose communication quality with respect to the base station is below a predetermined value, so that the communication quality with which each of the terminals connects to the base station exceeds the predetermined value.

The present invention makes it possible to optimize and select the base station to which each terminal should connect from among multiple base stations while maintaining a specified communication quality.

1 is a diagram showing an overview of a wireless communication system according to an embodiment; FIG. 2 is a functional block diagram illustrating functions of a terminal. FIG. 2 is a functional block diagram illustrating functions of a base station. FIG. 2 is a functional block diagram illustrating functions of a central station. 13 is a flowchart showing an example of the operation of the central station; FIG. 2 is a diagram illustrating an example of a hardware configuration of a central station according to an embodiment.

Below, a wireless communication system according to one embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing an overview of a wireless communication system 1 according to one embodiment. As shown in FIG. 1, the wireless communication system 1 according to one embodiment includes multiple central stations 4 that cooperate with each other to centrally control multiple base stations 3, each capable of accommodating multiple terminals 2.

The terminals 2 are wireless terminals that are used by users for wireless communication. The base stations 3 may be reflectors that relay radio waves. The central station 4 is configured to cooperate with other central stations 4 to centrally control a plurality of base stations 3.

Next, the functions of the terminal 2, base station 3, and central station 4 will be specifically explained using Figures 2 to 4.

FIG. 2 is a functional block diagram illustrating the functions of the terminal 2. As shown in FIG. 2, the terminal 2 has, for example, an antenna 20, an amplifier 21, an AD converter 22, a demodulator/decoder 23, an information bit detector 24, and a position information notification unit 25.

The amplifier 21 amplifies the signal received via the antenna 20 and outputs it to the AD converter 22. Note that a converter that converts the frequency may be provided in front of the amplifier 21.

The AD conversion unit 22 is an analog-to-digital conversion unit that converts the analog signal amplified by the amplifier unit 21 into a digital signal.

The demodulation and decoding unit 23 demodulates the received data that has been converted into a digital signal by the AD conversion unit 22, performs error correction decoding, and outputs the data to the information bit detection unit 24.

The information bit detection unit 24 detects information bits from the signal input from the demodulation and decoding unit 23.

The location information notification unit 25 generates a notification signal for notifying the base station 3 of information (terminal location information) indicating the location of the own station (the terminal 2), and notifies the base station 3 of the generated notification signal via the antenna 20.

FIG. 3 is a functional block diagram illustrating the functions of the base station 3. As shown in FIG. 3, the base station 3 has, for example, an antenna 30, an information bit generation unit 31, a modulation coding unit 32, a DA conversion unit 33, a wireless conversion unit 34, a wireless conversion unit 35, an AD conversion unit 36, a demodulation and decoding unit 37, an information bit detection unit 38, a power intensity detection unit 300, an obstacle information detection unit 302, and an environmental information detection unit 304.

The information bit generator 31 generates information bits indicating data to be transmitted to the terminal 2, and outputs them to the modulation and coding unit 32.

The modulation and coding unit 32 performs error correction coding on the information bits generated by the information bit generation unit 31, digitally modulates them into a data signal, and outputs the data signal to the DA conversion unit 33.

The DA conversion unit 33 converts the data signal digitally modulated by the modulation and coding unit 32 into an analog signal and outputs it to the wireless conversion unit 34.

The wireless conversion unit 34 converts the analog signal converted by the DA conversion unit 33 into a specified wireless signal and transmits it via the antenna 30.

The wireless conversion unit 35 converts the wireless signal received via the antenna 30 into an analog signal of a specific frequency and outputs it to the AD conversion unit 36.

The AD conversion unit 36 is an analog-to-digital conversion unit that converts the analog signal converted by the wireless conversion unit 35 into a digital signal.

The demodulation and decoding unit 37 demodulates the received data that has been converted into a digital signal by the AD conversion unit 36, performs error correction decoding, and outputs the data to the information bit detection unit 38.

The information bit detection unit 38 detects information bits from the signal input from the demodulation and decoding unit 37.

The power intensity detection unit 300 detects the power intensity of the signal received from each terminal 2 via the antenna 30, and notifies the central station 4. For example, the power intensity detection unit 300 detects the gain of each multipath for each delay time. The power intensity detection unit 300 may also have a function of detecting the distance to the terminal 2, the propagation loss between the terminal 2, etc.

The obstacle information detection unit 302 is an image sensor such as a CMOS sensor that detects obstacles that affect communication with the terminal 2, and performs processing to notify the central station 4 of information indicating the detected obstacle. For example, the obstacle information detection unit 302 captures an image of an object located between each terminal 2.

The environmental information detection unit 304 detects the surrounding environment that may affect communication with the terminal 2, and notifies the central station 4 of the environmental information indicating the detected surrounding environment.

The base station 3 is configured to have the function of transmitting to the central station 4, for example, the wireless quality status between the terminal 2 (propagation loss, fading environment, shadowing) and terminal location information indicating the location of the terminal 2 notified from the terminal 2.

FIG. 4 is a functional block diagram illustrating the functions of the central station 4. Note that the central station 4 is configured to have a function for linking with other central stations 4, so the other central stations 4 are also shown in a simplified form in FIG. 4.

As shown in FIG. 4, the central station 4 has, for example, a collection unit 40, a big data processing unit 42, a collaboration unit 44, a selection unit 46, and a change unit 48.

The collection unit 40 has, for example, a location information collection unit 402, a power intensity collection unit 404, an obstacle information collection unit 406, and an environmental information collection unit 408, and continuously collects terminal location information indicating the location of each terminal 2, and propagation loss information indicating the propagation loss between each terminal 2 and each base station 3, and outputs it to the big data processing unit 42.

For example, the location information collection unit 402 collects terminal location information indicating the location of each terminal 2 transmitted from the base station 3, and outputs the information to the big data processing unit 42.

The power intensity collection unit 404 collects power information indicating the intensity of the received power from each terminal 2 transmitted from the base station 3, and outputs it to the big data processing unit 42.

The obstacle information collection unit 406 collects information indicating obstacles that affect communication with the terminal 2 sent from the base station 3, and outputs the information to the big data processing unit 42.

The environmental information collection unit 408 collects environmental information indicating the surrounding environment that affects communication with the terminal 2 and is sent from the base station 3, and outputs the information to the big data processing unit 42.

In other words, the collection unit 40 has the function of collecting terminal position information and propagation loss information calculated based on the power intensity detected by the power intensity detection unit 300 of the base station 3 and the object photographed by the obstacle information detection unit 302.

The big data processing unit 42 generates a collection of big data of the CPS described above, and also has a calculation unit 420 and a determination unit 422, and performs processing to control the collaboration unit 44 and the change unit 48.

The calculation unit 420 calculates the packet error rate of each base station 3 once selected by the selection unit 46, as described below, based on, for example, the terminal position information and propagation loss information continuously collected by the collection unit 40, and outputs the packet error rate to the determination unit 422.

The determination unit 422 determines whether there is a terminal 2 whose communication quality with the base station 3 falls below a predetermined value based on the packet error rate calculated by the calculation unit 420.

The collaboration unit 44 collaborates with other central stations 4 to share the results of processing by the big data processing unit 42 with the other central stations 4 and output the results to the selection unit 46.

The selection unit 46 performs a process of selecting a base station 3 to which the terminal 2 should connect based on the results of processing by the big data processing unit 42, and outputs the processing result to the change unit 48. For example, the selection unit 46 predicts the traffic between each terminal 2 and each base station 3 based on the relevance of each user who uses the terminal 2, and selects a base station 3 to which the terminal 2 should connect based on the traffic of each terminal 2.

When the determination unit 422 determines that there is a terminal 2 whose communication quality with respect to the base station 3 falls below a predetermined value, the change unit 48 controls the base station 3 to change the base station 3 to which the terminal 2 is connected so that the communication quality of each terminal 2 connecting to the base station 3 exceeds the predetermined value.

The central station 4 is configured to generate a collection of big data using terminal location information indicating the location of each terminal collected via the base station 3, and actual data related to propagation loss (distance between the terminal 2 and the base station 3, shadowing due to obstacles, etc.), and to use this data together with the CPS big data described above to accurately select the base station 3 to which the terminal 2 should connect.

Next, an example of the operation of the central station 4 will be described. FIG. 5 is a flowchart showing an example of the operation of the central station 4. As shown in FIG. 5, for example, the central station 4 first collects actual data related to terminal position information and propagation loss for each terminal 2 (S100).

Next, the central station 4 calculates the wireless packet error rate for the selected base station using the CPS big data (S102).

Then, the central station 4 checks whether there is a terminal 2 for which the traffic volume for each packet error rate has decreased and fallen below the required predetermined communication quality (S104).

The central station 4 determines whether all terminals satisfy the required predetermined communication quality (S106), and if all terminals satisfy the communication quality (S106: Yes), ends the process, otherwise (S106: No), proceeds to the process of S108.

In the process of S108, the central station 4 performs a process to change the connected base station of each terminal 2, and returns to the process of S102.

In this way, the wireless communication system 1 according to one embodiment continuously collects terminal position information of each terminal 2 and propagation loss information indicating the propagation loss between each terminal 2 and each base station 3, and when there is a terminal 2 whose communication quality with respect to a base station 3 falls below a predetermined value, changes the base station 3 to which the terminal 2 is connected so that the communication quality exceeds the predetermined value, thereby making it possible to optimize and select the base station 3 to which each terminal 2 should connect from among multiple base stations 3 while maintaining a predetermined communication quality.

Furthermore, each function possessed by the terminal 2, base station 3, and central station 4 may be configured in whole or in part by hardware such as a PLD (Programmable Logic Device) or an FPGA (Field Programmable Gate Array), or may be configured as a program executed by a processor such as a CPU.

For example, the central station 4 can be realized using a computer and a program, and the program can be recorded on a storage medium or provided via a network.

FIG. 6 is a diagram showing an example of the hardware configuration of a central station 4 according to one embodiment. As shown in FIG. 6, the central station 4 has an input unit 50, an output unit 51, a communication unit 52, a CPU 53, a memory 54, and a HDD 55 connected via a bus 56, and functions as a computer. The central station 4 is also capable of inputting and outputting data to and from a computer-readable storage medium 57.

The input unit 50 is, for example, a keyboard and a mouse. The output unit 51 is, for example, a display device such as a display. The input unit 50 and the output unit 51 may also be a touch panel, etc.

The communication unit 52 is, for example, a communication interface that performs wireless communication.

The CPU 53 controls each component of the central station 4 and performs predetermined processing. The memory 54 and HDD 55 store data, etc.

The storage medium 57 is capable of storing programs and the like that execute the functions of the central station 4. Note that the architecture that constitutes the central station 4 is not limited to the example shown in FIG. 6.

1...wireless communication system, 2...terminal, 3...base station, 4...central station, 20...antenna, 21...amplifier, 22...AD converter, 23...demodulation and decoding unit, 24...information bit detector, 25...location information notification unit, 30...antenna, 31...information bit generator, 32...modulation and coding unit, 33...DA converter, 34...wireless converter, 35...wireless converter, 36...AD converter, 37...demodulation and decoding unit, 38...information bit detector, 40...collection unit, 42...bit data processing unit, 44... linking unit, 46... selection unit, 48... change unit, 50... input unit, 51... output unit, 52... communication unit, 53... CPU, 54... memory, 55... HDD, 56... bus, 57... storage medium, 300... power intensity detection unit, 302... obstacle information detection unit, 304... environmental information detection unit, 402... position information collection unit, 404... power intensity collection unit, 406... obstacle information collection unit, 408... environmental information collection unit, 420... calculation unit, 422... determination unit

Claims

In a wireless communication system having a plurality of central stations that cooperate with each other to centrally control a plurality of base stations each capable of accommodating a plurality of terminals,
The central station comprises:
A selection unit that predicts traffic between each of the terminals and each of the base stations based on the relevance of each of the users using the terminals, and selects the base station to which the terminals should be connected based on the traffic of each of the terminals;
A collection unit that continuously collects terminal location information indicating a location of each of the terminals and propagation loss information indicating a propagation loss between each of the terminals and each of the base stations;
a calculation unit that calculates a packet error rate of each of the base stations selected by the selection unit based on terminal location information and propagation loss information continuously collected by the collection unit;
a determination unit that determines whether or not there is a terminal whose communication quality with respect to the base station is below a predetermined value based on the packet error rate calculated by the calculation unit;
and a change unit that, when the determination unit determines that there is a terminal whose communication quality with respect to the base station is below a predetermined value, changes the base station to which the terminal is connected so that the communication quality of each of the terminals connected to the base station exceeds a predetermined value.
The base station,
a power intensity detection unit that detects the intensity of power received from each of the terminals;
and an image sensor for capturing an image of an object located between each of the terminals;
The collecting unit includes:
The wireless communication system according to claim 1 , further comprising: collecting terminal position information and propagation loss information calculated based on the power intensity detected by the power intensity detection unit and the object photographed by the image sensor.
In a central station that centrally controls a plurality of base stations, each of which can accommodate a plurality of terminals,
A selection unit that predicts traffic between each of the terminals and each of the base stations based on the relevance of each of the users using the terminals, and selects the base station to which the terminals should be connected based on the traffic of each of the terminals;
A collection unit that continuously collects terminal location information indicating a location of each of the terminals and propagation loss information indicating a propagation loss between each of the terminals and each of the base stations;
a calculation unit that calculates a packet error rate of each of the base stations selected by the selection unit based on terminal location information and propagation loss information continuously collected by the collection unit;
a determination unit that determines whether or not there is a terminal whose communication quality with respect to the base station is below a predetermined value based on the packet error rate calculated by the calculation unit;
and a change unit that, when the determination unit determines that there is a terminal whose communication quality with respect to the base station is below a predetermined value, changes the base station to which the terminal is connected so that the communication quality of each of the terminals connected to the base station exceeds a predetermined value.
The base station,
a power intensity detection unit that detects the intensity of power received from each of the terminals;
and an image sensor for capturing an image of an object located between each of the terminals;
The collecting unit includes:
The central station according to claim 3, further comprising: a power intensity detector that detects the power intensity and a terminal position information and a propagation loss information that are calculated based on the power intensity detected by the power intensity detector and the object photographed by the image sensor.
A wireless communication method in which a plurality of central stations cooperate to centrally control a plurality of base stations each capable of accommodating a plurality of terminals, comprising:
A selection step of predicting traffic between each of the terminals and each of the base stations based on the relevance of each of the users using the terminals, and selecting the base station to which the terminals should be connected based on the traffic of each of the terminals;
a collection step of continuously collecting terminal location information indicating a location of each of the terminals and propagation loss information indicating a propagation loss between each of the terminals and each of the base stations;
a calculation step of calculating a packet error rate of each of the base stations selected in the selection step based on the terminal location information and the path loss information continuously collected in the collection step;
a determination step of determining whether or not there is a terminal whose communication quality with respect to the base station is below a predetermined value based on the packet error rate calculated in the calculation step;
and when it is determined in the determination step that there is a terminal whose communication quality with respect to the base station is below a predetermined value, a change step of changing the base station to which the terminal is connected so that the communication quality of each of the terminals connected to the base station exceeds a predetermined value.
The base station,
a power intensity detection unit that detects the intensity of power received from each of the terminals;
and an image sensor for capturing an image of an object located between each of the terminals;
In the collecting step,
The wireless communication method according to claim 5 , further comprising: collecting terminal position information and propagation loss information calculated based on the power intensity detected by the power intensity detection unit and the object photographed by the image sensor.
A centralized control program for causing a computer to function as each part of the centralized station according to claim 3 or 4.