JP2014195191A - Method, device and program for communication quality estimation, and radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate communication quality between a base station 1 and a mobile terminal 2.SOLUTION: A communication quality estimation method includes: a step (S1) for generating terminal statistical information including a statistic value of a throughput on each communication trial basis, measured by a plurality of mobile terminals 2; a step (S2) for generating first base station statistical information including a statistic value of a base station throughput per mobile terminal 2, on the basis of a data amount received by a base station 1 from the plurality of mobile terminals 2 during a plurality of first measurement periods and the number of mobile terminals 2 transmitting the data during the plurality of first measurement period; and a step (S3) for generating first estimation statistical information, including the statistic value of the throughput of the base station 1 on each communication trial basis in the plurality of first measurement periods, on the basis of the first base station statistical information and the terminal statistical information.

Description

  The present invention relates to a communication quality estimation method, a communication quality estimation apparatus, a communication quality estimation program, and a radio communication system related to estimation of communication quality between a mobile terminal and a base station.

  Conventionally, in order to improve the communication quality between a mobile terminal and a base station in a wireless communication system, the measurement result of the communication quality in each mobile terminal is transmitted to the base station, and the base station carries the mobile based on the measurement result. A method of controlling data transmission / reception with a terminal is known (see, for example, Patent Document 1).

  In addition, in a wireless communication system using the OFDMA scheme, the base station smoothes channel quality information collected from mobile terminals for each subframe and estimates the quality, thereby reducing the effect of temporary quality fluctuations. A method for scheduling wireless channels is also known (see, for example, Patent Document 2).

JP 2003-318861 A JP 2012-124585 A

  According to the method described in Patent Literature 1, the communication quality measurement result in each mobile terminal is transmitted to the base station. However, when each mobile terminal transmits the measurement result to the base station, the radio channel is used to transmit the measurement result, and the radio channel that can be used by the mobile terminal decreases. There is a problem in that it causes deterioration.

  According to the method described in Patent Document 2, since channel quality information is received from the mobile terminal for each subframe, the base station needs to frequently aggregate channel quality information. Therefore, this method has a problem that the processing load on the base station is large. In particular, when the number of mobile terminals accommodated in one base station increases, the load on the base station that receives channel quality information from a large number of mobile terminals increases.

  Therefore, the present invention has been made to solve these problems, and communication between a mobile terminal and a base station can be performed without excessive use of a radio channel or excessive load on the base station. The purpose is to be able to estimate the quality of the.

  The communication quality estimation method according to the first aspect of the present invention includes a step of generating terminal statistical information including a statistical value of throughput of communication trial units measured in a plurality of portable terminals, and a plurality of first measurement periods Based on the amount of data received by the base station from the plurality of portable terminals and the number of the portable terminals that transmitted the data during the plurality of first measurement periods, the first throughput is a throughput per portable terminal. Based on the first base station statistical information including the statistical value of the base station throughput and the first base station statistical information and the terminal statistical information, the base station within the plurality of first measurement periods Generating first estimated statistical information including a statistical value of throughput in communication trial units.

  The step of generating the terminal statistical information includes, for example, receiving a measured value of throughput in communication trial units and position information indicating the position of each mobile terminal from the plurality of mobile terminals; For each area to which the corresponding position belongs, calculating an average and variance of the measured values, and generating relationship information indicating a relationship between the average and the variance, and the first estimated statistics In the step of generating information, the first estimated statistical information is generated based on the first base station statistical information and the relationship information.

  The step of generating the first estimated statistical information includes generating a plurality of statistical distribution information based on an average value of the first base station throughput and the relationship information, and in the plurality of first measurement periods, Generating a plurality of weighted statistical information by weighting each of the plurality of statistical distribution information based on a probability of occurrence of an average value, and adding each of the plurality of weighted statistical information; Generating estimated statistical information.

  In the communication quality estimation method, after the step of generating the first estimated statistical information, the amount of data received from the plurality of mobile terminals by the base station during a plurality of second measurement periods, and the plurality of second Generating second base station statistical information including a statistical value of second base station throughput, which is a throughput per mobile terminal, based on the number of mobile terminals that transmitted the data during a measurement period; Generating second estimated statistical information including statistical values of throughput of communication trial units in the base stations within the plurality of second measurement periods based on the second base station statistical information and the terminal statistical information; Based on the second estimated statistical information and difference information indicating a difference between a statistical value included in the terminal statistical information and a statistical value included in the first estimated statistical information, the plurality of second measurement periods A step of generating a third estimate statistics including statistics of throughput of the communication trial unit in the portable terminal may further comprise a.

  The step of generating the third estimated statistical information includes, for example, the throughput of the communication trial unit included in the terminal statistical information with respect to the mode value or average value of the throughput of the communication trial unit included in the first estimated statistical information. Based on the step of calculating a reduction rate of the mode value or the average value, and the second estimated statistical information and the reduction rate, the mode of throughput of the communication trial unit in the mobile terminal in the plurality of second measurement periods. Calculating a value or an average value.

  The step of generating the third estimated statistical information includes a variance or standard deviation of throughput of communication trial units included in the terminal statistical information with respect to a variance or standard deviation of throughput of communication trial units included in the first estimated statistical information. Calculating a variance or standard deviation of throughput of communication trial units in the mobile terminal in the plurality of second measurement periods based on the second estimated statistical information and the reduction rate You may have.

  In the communication quality estimation method, after the step of generating the third estimated statistical information, determination criterion information indicating a criterion for determining whether the throughput of the communication trial unit in the mobile terminal is good or not indicated by the third estimated statistical information A step of determining whether the throughput of the communication trial unit in the mobile terminal is good or bad, based on the determination criterion information, and determining whether the third estimated statistical information is good or bad In accordance with the result, the step of determining whether the throughput of the communication trial unit in the base station is good or bad indicated by the second estimated statistical information used for the estimation of the third estimated statistical information, and the second estimated statistical information Associating and storing in a storage unit a communication quality criterion indicating whether the communication quality is good, and based on the communication quality criterion, the base station Serial determining the quality of the communication quality between the mobile terminal may further comprise a.

  In the communication quality estimation method, after the step of generating the third estimated statistical information, determination criterion information indicating a criterion for determining whether the throughput of the communication trial unit in the mobile terminal is good or not indicated by the third estimated statistical information A step of determining whether the throughput of the communication trial unit in the mobile terminal is good or bad, based on the determination criterion information, and determining whether the third estimated statistical information is good or bad According to the result, determining whether the second base station statistical information corresponding to the third estimated statistical information and the second base station throughput are acceptable, the second base station statistical information and the second base station statistical information Storing in a storage unit a communication quality criterion indicating whether the communication quality is good or bad in association with one of the base station throughputs, and the communication quality criterion Based on, determining the quality of the communication quality between the mobile terminal and the base station may further comprise a.

  A communication quality estimation program according to a second aspect of the present invention includes a step of generating terminal statistical information including a statistical value of throughput of communication trial units measured in a plurality of portable terminals in a computer; Throughput per mobile terminal based on the amount of data received by the base station from the plurality of mobile terminals during the measurement period and the number of mobile terminals that transmitted the data during the plurality of first measurement periods Generating the first base station statistical information including the statistical value of the first base station throughput, and based on the first base station statistical information and the terminal statistical information within the plurality of first measurement periods Generating first estimated statistical information including a statistical value of throughput of communication trial units in the base station.

  The communication quality estimation program may include the amount of data received by the base station from the plurality of mobile terminals in a plurality of second measurement periods after the step of generating the first estimation statistical information in the computer, Based on the number of the mobile terminals that transmitted the data during the plurality of second measurement periods, second base station statistical information including a statistical value of the second base station throughput that is a throughput per mobile terminal is generated. Based on the second base station statistical information and the terminal statistical information, second estimated statistical information including a statistical value of throughput of communication trial units in the base station within the plurality of second measurement periods is obtained. Based on the generating step, the second estimated statistical information, and difference information indicating a difference between the terminal statistical information and the first estimated statistical information. At least one of the step of generating third estimated statistical information including a statistical value of throughput of communication trial unit in the portable terminal, the first estimated statistical information, the second estimated statistical information, and the third estimated statistical information And a step of displaying the included statistical value may be further executed.

  A communication quality estimation apparatus according to a third aspect of the present invention includes: a first generation unit that generates terminal statistical information including a statistical value of throughput of communication trial units measured in the plurality of mobile terminals; Throughput per mobile terminal based on the amount of data received by the base station from the plurality of mobile terminals during the measurement period and the number of mobile terminals that transmitted the data during the plurality of first measurement periods A plurality of first measurements based on the second generation unit for generating first base station statistical information including statistical values of the first base station throughput, and the first base station statistical information and the terminal statistical information. A third generation unit that generates first estimated statistical information including a statistical value of throughput of communication trial units in the base station within a period.

  The communication quality estimation apparatus includes: an amount of data received by the base station from the plurality of portable terminals during a plurality of second measurement periods; and a number of the portable terminals that transmitted the data during the plurality of second measurement periods. A fourth generation unit that calculates second base station statistical information including a statistical value of the second base station throughput, which is a throughput per mobile terminal, the second base station statistical information, and the terminal statistics A fifth generation unit that generates second estimated statistical information including statistical values of throughput of communication trial units in the base station within the plurality of second measurement periods based on the information, the second estimated statistical information, A third estimate including a statistical value of throughput of communication trial units in the portable terminal within the plurality of second measurement periods based on difference information indicating a difference between the terminal statistical information and the first estimated statistical information Command A sixth generation unit for generating information may further comprise a.

  A wireless communication system according to a fourth aspect of the present invention estimates a base station, a plurality of mobile terminals capable of communicating with the base station, and a communication quality between the base station and the plurality of mobile terminals. A wireless communication system including a communication quality estimation device, wherein a first generation unit that generates terminal statistical information including a statistical value of throughput of communication trial units measured in the plurality of mobile terminals, and a plurality of first measurement periods The throughput per mobile terminal based on the amount of data received by the base station from the plurality of mobile terminals and the number of mobile terminals that transmitted the data during the plurality of first measurement periods. Based on the second generation unit that generates first base station statistical information including statistical values of the first base station throughput, the first base station statistical information, and the terminal statistical information, in the plurality of first measurement periods Of the above And a third generation unit for generating a first estimated statistics including statistics of throughput of the communication trial unit in Chikyoku, and a storage unit that stores the terminal statistical information and the first estimated statistics.

  The wireless communication system includes: an amount of data received from the plurality of mobile terminals by the base station during a plurality of second measurement periods; and a number of the mobile terminals that transmit the data during the plurality of second measurement periods. A fourth generation unit for calculating second base station statistical information including a statistical value of the second base station throughput, which is a throughput per mobile terminal, the second base station statistical information, and the terminal statistical information A fifth generation unit that generates second estimated statistical information including a statistical value of throughput of a communication trial unit in the base station within the plurality of second measurement periods, and the second estimated statistical information; Based on difference information indicating a difference between the terminal statistical information and the first estimated statistical information, a third estimated statistics including a statistical value of a throughput of communication trial units in the mobile terminal within the plurality of second measurement periods. A sixth generation unit for generating information may further comprise a.

1 shows an overview of a wireless communication system according to the present embodiment. The structural example of the communication quality estimation apparatus which concerns on this embodiment is shown. The flowchart of the operation | movement which a communication quality estimation apparatus estimates communication quality is shown. The average and dispersion | distribution relationship of the user throughput information in the several area which the 1st production | generation part produced | generated is shown. The cumulative distribution function when the first base station throughput is approximated by a lognormal distribution is shown. A cumulative distribution function of a plurality of lognormal distributions is shown. The logarithmic normal distribution which the 3rd generation part generated is shown. The relationship between the terminal statistical information and 1st estimated statistical information memorize | stored in the memory | storage part, and the 1st estimated statistical information estimated based on the base station throughput measured in the base station is shown. The outline | summary of the process which produces | generates 3rd estimation statistical information is shown. The distribution of the throughput of the communication trial unit in the estimated portable terminal is shown. An example of the 3rd estimation statistical information used for determination of quality of communication quality is shown.

[Outline of Wireless Communication System S]
FIG. 1 shows an overview of a wireless communication system S according to the present embodiment.
The wireless communication system S includes a base station 1 of a mobile phone network, a plurality of mobile terminals 2 (for example, a mobile terminal 2-1 and a mobile terminal 2-2), and a communication quality estimation device 3. The base station 1 and each mobile terminal 2 are connected by a wireless communication line. The communication quality estimation device 3 estimates the communication quality of communication between the base station 1 and the mobile terminal 2.

  The base station 1 and the communication quality estimation device 3 are connected via a network N so as to be communicable. The network N is, for example, the Internet. The plurality of portable terminals 2 and the communication quality estimation device 3 are connected to be communicable via the base station 1 and the network N. Note that the plurality of mobile terminals 2 may be communicably connected to the communication quality estimation device 3 via the Wi-Fi access point and the network N.

[Measurement of user throughput in portable terminal 2]
Prior to the communication quality estimation device 3 performing the operation of estimating the communication quality, each mobile terminal 2 measures the throughput of the communication trial unit using the throughput measurement program installed in advance. Here, “communication trial unit” means one operation from the start of communication by the mobile terminal 2 to the end of communication. “Throughput” is the amount of data transmission per unit time. Therefore, “throughput in communication trial unit” means the amount of data transmission per unit time in one operation from when the mobile terminal 2 starts communication until the communication ends.

  In the present specification, the throughput of the communication trial unit measured in the mobile terminal 2 may be referred to as “user throughput”. The size of the user throughput affects the comfort that the user of the mobile terminal 2 feels when acquiring a Web page, moving image content, and the like.

  The mobile terminal 2 measures the user throughput by measuring the amount of data transmitted to the base station 1 between the start of communication and the end of communication, and dividing the transmitted data amount by the communication time. The mobile terminal 2 associates the user throughput information including the measured value of the user throughput with the position information indicating the position where the communication is performed, and transmits the associated information to the communication quality estimation apparatus 3. The mobile terminal 2 measures a plurality of user throughputs within a predetermined period, and transmits a plurality of user throughput information to the communication quality estimation apparatus 3. In addition, the measurement of the user throughput by the portable terminal 2 is performed, for example, every several months to one year so as to cope with the change in the tendency of the user throughput accompanying the change in the communication environment.

[Configuration Example of Communication Quality Estimation Device 3]
FIG. 2 shows a configuration example of the communication quality estimation apparatus 3 according to the present embodiment. The communication quality estimation device 3 is a server, for example. The communication quality estimation device 3 includes a storage unit 31, a communication unit 32, a display unit 33, and a control unit 34.

  The storage unit 31 is configured by, for example, a ROM and a RAM. The storage unit 31 stores various programs for causing the mobile terminal 2 to function. The storage unit 31 may read and store a program stored in a storage medium such as an external memory or a CD-ROM, or may store a program downloaded from an external device via the network N.

The communication unit 32 communicates with the base station 1 or the mobile terminal 2 via the network N under the control of the control unit 34. The communication unit 32 is, for example, a communication controller.
The display unit 33 is configured by, for example, a liquid crystal display, an organic EL (Electro-Luminescence) display, or the like. The display unit 33 displays characters, graphics, and the like according to the control of the control unit 34.

  The control part 34 is comprised by CPU, for example. The control unit 34 comprehensively controls functions related to the communication quality estimation device 3 by executing a communication quality estimation program stored in the storage unit 31. Specifically, the control unit 34 executes a communication quality estimation program, thereby generating a first generation unit 341, a second generation unit 342, a third generation unit 343, a fourth generation unit 344, and a fifth generation unit 345. , Function as a sixth generation unit 346 and a determination unit 347.

[Description of operation for estimating communication quality]
FIG. 3 shows a flowchart of an operation in which the communication quality estimation device 3 estimates the communication quality. Hereinafter, the operation of each unit of the control unit 34 will be described with reference to FIGS. 2 and 3.

  First, for each area of a predetermined size, the first generation unit 341 obtains statistical values of a plurality of user throughput information acquired from the mobile terminal 2 in association with position information indicating positions included in each area. Including terminal statistical information is generated (S1). Specifically, first, the first generation unit 341 receives user throughput information including an actual measurement value of user throughput in the mobile terminal 2 and position information indicating the position of each mobile terminal 2 via the communication unit 32. Receive.

  Next, the 1st production | generation part 341 calculates the average and dispersion | distribution of the measured value of user throughput for every area to which the position corresponding to position information belongs. The first generation unit 341 approximates the distribution of user throughput to, for example, a log normal distribution, and stores it in the storage unit 31 as terminal statistical information. Further, the first generation unit 341 generates relationship information indicating the relationship between the average and the variance based on the relationship between the average and the variance of the plurality of user throughput information.

FIG. 4 shows the relationship between the average and variance of user throughput information in a plurality of areas generated by the first generation unit 341. Each point shown in FIG. 4 is an average of user throughput information in each of a plurality of 500 m square areas determined in advance by dividing an area of several tens km square into a mesh shape. Indicates dispersion. When the average E (X) and the variance V (X) are distributed as in the example illustrated in FIG. 4, the first generation unit 341 determines that V (X) = (1.05 × E (X) +60) ^The relation information represented by the relational expression ² is generated.

  Subsequently, the second generation unit 342 receives the amount of data received from the plurality of mobile terminals 2 by the base station 1 during a plurality of first measurement periods, and the number of mobile terminals 2 that transmit data during the plurality of first measurement periods. Based on the above, the first base station statistical information including the statistical value of the first base station throughput which is the throughput per mobile terminal 2 is generated (S2). Specifically, the second generation unit 342 is configured so that each of the plurality of base stations 1 installed in an area (for example, an area of several tens of km squares) for which the first base station statistical information is calculated is the first Information indicating the amount of data received from a plurality of mobile terminals 2 during a time (for example, 5 minutes) determined as a measurement period, and information indicating the number of mobile terminals 2 with which each base station 1 communicated during the first measurement period And get. Next, the second generation unit 342 calculates the amount of data communication per mobile terminal 2 by dividing the amount of measured data by the number of mobile terminals 2 that communicated during the first measurement period.

  Subsequently, the second generation unit 342 divides the calculated data communication amount by the communication time (for example, 5 minutes × 60 seconds = 300 seconds), thereby performing data communication per second per mobile terminal 2. The first base station throughput, which is a quantity, is calculated. For example, based on the data communication amount measured every 5 minutes over 24 hours, the second generation unit 342 indicates 24 hours × 60 minutes ÷ 5 minutes = 288 first base station throughputs per base station 1 Information can be obtained. The second generation unit 342 obtains information indicating the number of base stations 1 installed in an area for which the first base station statistical information is calculated × 288 first base station throughputs.

  The second generation unit 342 generates first base station statistical information indicating the distribution of the first base station throughput by calculating the average and variance of the plurality of first base station throughputs. The second generation unit 342 may generate the first base station statistical information by approximating the first base station throughput with a predetermined statistical distribution. For example, the second generation unit 342 generates first base station statistical information by approximating the first base station throughput with a lognormal distribution.

  FIG. 5 shows a cumulative distribution function when the first base station throughput is approximated by a lognormal distribution. The horizontal axis in FIG. 5 indicates the average value of the first base station throughput measured at an arbitrary base station 1, and the vertical axis indicates the value of the cumulative distribution function. Here, the average value of the first base station throughput is an average value of a plurality of first base station throughputs measured every 5 minutes in an arbitrary base station 1. In FIG. 5, it is shown that the average value of the first base station throughput is widely distributed between about 800 kbps and about 1600 kbps.

  Subsequently, based on the first base station statistical information and the terminal statistical information, the third generation unit 343 includes the first estimation including the statistical value of the throughput of the communication trial unit in the base station 1 within the plurality of first measurement periods. Statistical information is estimated (S3). Specifically, the third generation unit 343 generates the first estimated statistical information based on the first base station statistical information generated by the second generation unit 342 and the relationship information generated by the first generation unit 341. presume.

  More specifically, first, the third generation unit 343 generates a plurality of statistical distribution information approximated using a lognormal distribution based on an average value of a plurality of first base station throughputs and the above relationship information. Generate. For example, the third generation unit 343 determines that the relationship between the average and the variance of the average values of the plurality of first base station throughputs constituting the first base station statistical information is the terminal statistical information generated by the first generation unit 341. Assuming that the relationship between the mean and variance indicated by is equal, the relationship between the mean and variance of each of a plurality of average values is calculated to obtain a plurality of lognormal distributions.

The third generation unit 343 determines the first base station throughput measured by E (X) in the relational expression V (X) = (1.05 × E (X) +60) ² generated by the first generation unit 341. By substituting the average value, the variance when the average value of the first base station throughput becomes the substituted average value is calculated. For example, the third generation unit 343 calculates the variance of the first base station throughput measured with an average value of 10 kbps by substituting 10 kbps into E (X). Based on the average value and the variance, the third generation unit 343 generates a lognormal distribution cumulative distribution function as statistical distribution information corresponding to each average value.

  FIG. 6 shows a cumulative distribution function of a plurality of lognormal distributions generated by the third generation unit 343 based on the average value and the variance. The smaller the average value is, the closer the curve of the cumulative distribution function is to the curve a, and the larger the average value is, the closer the curve of the cumulative distribution function is to the curve b.

  Subsequently, the third generation unit 343 generates a plurality of weighted statistical information by weighting each of the plurality of statistical distribution information based on the probability that each average value has occurred in the plurality of first measurement periods. . Further, the third generation unit 343 generates first estimated statistical information by adding each of the plurality of weighted statistical information. For example, when the cumulative distribution function of the average value of the first base station throughput is as shown in FIG. 5, the probability that the average value is 1000 kbps to 1500 kbps is higher than the probability that the average value is another value. Therefore, the third generation unit 343 sets the weight of the log normal distribution when the average value is 1000 kbps to 1500 kbps to be larger than the weight of the log normal distribution when the average value is another value.

  Subsequently, the third generation unit 343 generates one log normal distribution that is the first estimated statistical information of the throughput of the communication trial unit in the base station 1 by adding a plurality of weighted log normal distributions. The third generation unit 343 stores the generated first estimated statistical information in the storage unit 31 (S4).

  FIG. 7 shows one lognormal distribution generated by the third generation unit 343. A curve c in FIG. 7 is a lognormal distribution corresponding to the first estimated statistical information. It can be seen that the lognormal distribution indicated by the curve c is located between the lognormal distribution indicated by the curve a and the lognormal distribution indicated by the curve b.

  FIG. 8 shows the relationship between the first base station statistical information, the first estimated statistical information, and the terminal statistical information. A one-dot chain line in FIG. 8 indicates a cumulative distribution function of the first base station statistical information corresponding to the first base station throughput measured in the base station 1. A solid line in FIG. 8 indicates the cumulative distribution function of the first estimated statistical information corresponding to the throughput of the communication trial unit in the base station 1. A broken line in FIG. 8 indicates a cumulative distribution function of terminal statistical information corresponding to the user throughput measured in the mobile terminal 2.

  It can be seen from FIG. 8 that there is a difference between the statistical value included in the first estimated statistical information and the statistical value included in the terminal statistical information. The statistical value included in the terminal statistical information is an average, variance, or standard deviation of throughput of communication trial units measured in the mobile terminal 2. The statistical value included in the first estimated statistical information is the average, variance, or standard deviation of the throughput of the communication trial unit in the base station 1, which is generated by estimation by the third generation unit 343.

  For example, when the value of the cumulative distribution function is 50%, the user throughput indicated by the terminal statistical information is about 60% of the throughput of the communication trial unit in the base station 1 indicated by the first estimated statistical information. is there. That is, a difference d exists between the statistical value included in the terminal statistical information and the statistical value included in the first estimated statistical information. The relationship between the terminal statistical information generated based on the user throughput measured under a predetermined condition and the first estimated statistical information generated based on the first base station throughput measured under the same condition is measured Even if the conditions such as the time zone are changed, it is considered that they are almost the same.

  Therefore, by using information indicating the relationship between the statistical value of the terminal statistical information stored in the storage unit 31 and the statistical value of the first estimated statistical information, the base station 1 has measured the information within a plurality of second measurement periods. Based on the second base station throughput, the user throughput during the period in which the second base station throughput is measured can be estimated. Specifically, the control unit 34 performs the processes of S5 to S7 to obtain the log-normal distribution corresponding to the first estimated statistical information without acquiring the user throughput information measured in the mobile terminal 2. The user throughput is estimated when the average is an arbitrary value.

Hereinafter, processing for estimating user throughput will be described.
The fourth generation unit 344 receives data received from a plurality of mobile terminals 2 during a plurality of second measurement periods by an arbitrary base station 1 among the plurality of base stations 1 used for calculating the first base station statistical information. And the statistical value of the second base station throughput, which is the throughput per mobile terminal 2 in the base station 1, based on the amount of the mobile terminal 2 and the number of mobile terminals 2 that transmitted data in a plurality of second measurement periods. The 2nd base station statistical information including is produced | generated (S5). During the plurality of second measurement periods, the amount of data transmitted from the mobile terminal 2 to the base station 1 used in the process (S2) in which the second generation unit 342 generates the first base station statistical information was measured. It is a period after the plurality of first measurement periods. The fourth generation unit 344 generates the second base station statistical information in the same procedure as the process in which the second generation unit 342 generates the first base station statistical information in S2.

  Subsequently, the fifth generation unit 345 includes, based on the second base station statistical information and the terminal statistical information, the second estimation including the statistical value of the throughput of the communication trial unit in the base station 1 within the plurality of second measurement periods. Statistical information is generated (S6). The process in which the fifth generation unit 345 generates the second estimated statistical information is the same process as the process in which the third generation unit 343 generates the first estimated statistical information in S3.

  Subsequently, the sixth generation unit 346 is based on the second estimated statistical information and difference information indicating a difference between the statistical value included in the first estimated statistical information and the statistical value included in the terminal statistical information. Third estimated statistical information including statistical values of throughput of communication trial units in the mobile terminals 2 within a plurality of second measurement periods is generated (S7).

  FIG. 9 shows an overview of a process in which the sixth generation unit 346 generates the third estimated statistical information. A solid line in FIG. 9 indicates a lognormal distribution corresponding to the first estimated statistical information stored in the storage unit 31. A broken line indicates a lognormal distribution corresponding to the terminal statistical information stored in the storage unit 31. A one-dot chain line indicates a lognormal distribution corresponding to the second estimated statistical information.

  As the difference information, the sixth generation unit 346, for example, the rate of decrease in the mode of throughput of the communication trial unit included in the terminal statistical information with respect to the mode of throughput of the communication trial unit included in the first estimated statistical information. X is calculated, and the rate of decrease Y of the throughput mode of the communication trial unit included in the third estimated statistical information with respect to the mode of throughput of the communication trial unit included in the second estimated statistical information is equal to the rate of decrease X Assuming that, a lognormal distribution corresponding to the third estimated statistical information indicated by the two-dot chain line in FIG. 9 is generated. Hereinafter, a procedure in which the sixth generation unit 346 generates the third estimated statistical information will be described.

  First, the sixth generation unit 346 calculates the mode value or average value of the throughput of communication trial units included in the terminal statistical information with respect to the mode value or average value of throughput of the communication trial units included in the first estimated statistical information. Calculate the reduction rate. Next, the sixth generation unit 346 calculates the mode or average value of the throughput of the communication trial unit in the mobile terminal 2 based on the calculated decrease rate. Specifically, the sixth generation unit 346 calculates the decrease rate of the mode value by 1− (mode value of terminal statistical information / mode value of first estimated statistical information). The sixth generation unit 346 may calculate the decrease rate of the average value by 1− (average value of terminal statistical information / average value of first estimated statistical information).

  In addition, the sixth generation unit 346 calculates the mode value of the throughput of the communication trial unit in the mobile terminal 2 by the mode value of the second estimated statistical information × (1−moderate decrease rate). The sixth generation unit 346 may calculate the average value of the throughput of the communication trial unit in the mobile terminal 2 by the average value of the second estimated statistical information × (1−the decrease rate of the average value).

Subsequently, the sixth generation unit 346 calculates the rate of decrease in the throughput or standard deviation of the communication trial unit included in the terminal statistical information with respect to the distribution or standard deviation of the throughput of the communication trial unit included in the first estimated statistical information. calculate. Next, the sixth generation unit 346 calculates the variance or standard deviation of the throughput of the communication trial unit in the mobile terminal 2 based on the calculated decrease rate. Specifically, the sixth generation unit 346 calculates the decrease rate of the standard deviation by 1− (standard deviation of terminal statistical information / standard deviation of first estimated statistical information). The sixth generation unit 346 may calculate the decrease rate of the variance by 1− (dispersion of terminal statistical information / dispersion of first estimated statistical information). Subsequently, the sixth generation unit 346 calculates the variance of the throughput of the communication trial unit in the mobile terminal 2 by {standard deviation of second estimated statistical information × (1−standard deviation reduction rate)} ² .

  Through the above procedure, the sixth generation unit 346 estimates the distribution of throughput in communication trial units in the mobile terminal 2 by calculating the mode of throughput in communication trial units in the mobile terminal 2 and the estimated value of variance. be able to.

  FIG. 10 shows the throughput distribution of communication trial units in the mobile terminal 2 estimated by the above procedure. As in FIG. 9, the solid line indicates a lognormal distribution corresponding to the first estimated statistical information stored in the storage unit 31. A broken line indicates a lognormal distribution corresponding to the terminal statistical information stored in the storage unit 31. A one-dot chain line indicates a lognormal distribution corresponding to the second estimated statistical information. A two-dot chain line indicates a lognormal distribution corresponding to the third estimated statistical information.

  From FIG. 10, the relationship between the second estimated statistical information corresponding to the throughput of the communication trial unit in the base station 1 and the third estimated statistical information corresponding to the user throughput corresponds to the throughput of the communication trial unit in the base station 1. It can be seen that the relationship between 1 estimated statistical information and terminal statistical information corresponding to user throughput is almost equal. The control unit 34 may cause the display unit 33 to display a statistical value included in at least one of the first estimated statistical information, the second estimated statistical information, and the third estimated statistical information.

[Judge the quality of communication quality]
The communication quality estimation device 3 can determine whether the communication quality between the mobile terminal 2 and the base station 1 is good or not based on the third estimated statistical information generated by the sixth generation unit 346.
The determination unit 347 acquires determination criterion information indicating a criterion for determining whether the throughput of the communication trial unit in the mobile terminal 2 is acceptable or not, which is indicated by the third estimated statistical information generated by the sixth generation unit 346. For example, the criterion information determines that “communication quality is good” when 60% or more of the throughput of the communication trial unit in the mobile terminal 2 is 300 kbps or more, and “communication quality” when less than 60% of the throughput is 300 kbps or more. Information for determining that the quality is “bad” and stored in the storage unit 31.

  Next, the determination unit 347 is a communication trial unit in the base station 1 indicated by the second estimated statistical information used to generate the third estimated statistical information according to the determination result of the quality of the third estimated statistical information. The quality of the throughput is determined. If the second base station statistical information (unit time average value) is greater than the average value of the second estimated statistical information corresponding to the user throughput determined to be “good communication quality”, the determining unit 347 determines that the base station 1 It is determined that “communication quality is good” based on the throughput of the communication trial unit. For example, when the average value of the second estimated statistical information when 800% or more of the user throughput is 300 kbps is 800 kbps, or when the second base station statistical information (unit time average value) is 800 kbps or more, the determination unit 347 And “communication quality is good”.

  The determination unit 347 causes the storage unit 31 to store a communication quality determination criterion indicating whether the communication quality is good or bad in association with the second estimated statistical information. Specifically, the determination unit 347 stores the quality of communication quality in the storage unit 31 in association with the statistical value of the throughput of the communication trial unit in the base station 1 or the shape of the statistical distribution. In this way, the determination unit 347 determines the communication quality between the mobile terminal 2 and the base station 1 based on the second estimated statistical information and the communication determination criterion information generated by the fifth generation unit 345. Judge the quality. Therefore, the determination unit 347 can determine the quality of the communication quality based on the throughput of the communication trial unit in the base station 1 without using the throughput measured in the mobile terminal 2. As a result, when the determination unit 347 determines that the communication quality is poor, the control unit 34 notifies the base station 1 or displays the fact on the display unit 33 so that the base station 1 It becomes possible to take measures such as changing the wireless communication line to be used.

  Note that the determination unit 347 determines the quality of the second base station throughput indicated by the second base station statistical information corresponding to each third estimated statistical information, according to the determination result of the quality of the third estimated statistical information. May be. Further, the determination unit 347 stores a communication quality determination criterion indicating whether the communication quality is good or not in the storage unit 31 in association with either the second base station statistical information or the second base station statistical information, and the second base station statistical information The quality of the communication quality between the mobile terminal 2 and the base station 1 may be determined based on either of the second base station throughput and the communication quality determination reference information. In this way, the communication quality estimation device 3 can determine whether the communication quality is good or not based on the second base station throughput, which is the throughput per mobile terminal 2 measured in the base station 1. it can.

  FIG. 11 shows an example of third estimated statistical information used for determining the quality of communication quality. The solid line, the one-dot chain line, and the two-dot chain line in FIG. 11 indicate the cumulative distribution functions of different third estimated statistical information. Here, the average value of the second estimated statistical information corresponding to the third estimated information of the solid line is 800 kbps, the average value of the second estimated statistical information corresponding to the third estimated information of the one-dot chain line is 600 kbps, It is assumed that the average value of the second estimated statistical information corresponding to the three estimated information is 400 kbps.

  Here, when the criterion for determining the quality of the communication quality based on the third estimated statistical information is “60% or more of the user throughput is 300 kbps or more”, the value of the cumulative distribution function when the throughput is 300 kbps is 0. If it is less than .4, it is determined that “communication quality is good”, and if the value of the cumulative distribution function when the throughput is 300 kbps is 0.4 or more, it is determined that “communication quality is bad”. Therefore, only the third estimated statistical information indicated by the solid line in the third estimated statistical information illustrated in FIG. 11 is determined to be “good”.

  In addition, when the average value of the second estimated statistical information corresponding to the third estimated statistical information indicated by the solid line is 800 kbps, the criterion for determining the quality of the communication quality based on the second base station statistical information is “No. The average value of the unit time of two base station throughputs is 800 kbps or more ”. For example, when determining the quality of communication quality every 5 minutes, the determination unit 347 determines the quality of communication quality based on whether the second base station throughput is 800 kbps or higher. For example, when determining the quality of the communication quality every hour, the determination unit 347 determines the quality of the communication quality based on whether the average value of the second base station throughput for one hour is 800 kbps or more.

[Effect in this embodiment]
The communication quality estimation apparatus 3 according to the present embodiment generates terminal statistical information including a statistical value of throughput of communication trial units measured in a plurality of mobile terminals 2, and is the throughput per mobile terminal 2. 1st base station statistical information including the statistical value of 1 base station throughput is generated, and 1st including the statistical value of throughput of communication trial unit in the base station 1 based on the first base station statistical information and the terminal statistical information Generate estimated statistics. By doing in this way, the base station 1 can estimate the throughput for each communication trial without actually measuring the throughput for each communication trial. As a result, there is an effect that the quality of communication between the mobile terminal and the base station can be estimated without excessive use of the radio channel or excessive load on the base station.

  In addition, the communication quality estimation device 3 calculates the average and variance of the actual measurement values for each area to which the position corresponding to the location information belongs, and generates relationship information indicating the relationship between the average and the variance. First estimated statistical information is generated based on the station statistical information and the relationship information. By doing in this way, the communication quality estimation apparatus 3 can estimate the throughput of the communication trial unit in consideration of the variation of the user throughput depending on the position of the mobile terminal 2.

  Further, the communication quality estimation device 3 generates a plurality of statistical distribution information based on the average value of the first base station throughput and the relation information, and a plurality of statistical distribution information based on the probability that the average value has occurred. Is weighted to generate first estimated statistical information. By doing in this way, the communication quality estimation apparatus 3 can improve the estimation accuracy of the throughput of the communication trial unit.

  Further, the communication quality estimation device 3 estimates based on the second base station throughput measured by the base station 1 during a period different from the period during which the first base station throughput used to generate the first estimated statistical information is measured. Based on the second estimated statistical information and the difference information indicating the difference between the statistical value included in the terminal statistical information and the statistical value included in the first estimated statistical information, Third estimated statistical information including the statistical value is generated. By doing in this way, the throughput in the portable terminal 2 can be estimated without actually measuring the throughput in the portable terminal 2.

  In addition, the communication quality estimation device 3 stores a communication quality determination criterion indicating the quality of communication quality in the storage unit in association with the second estimated statistical information, and the base station 1 and the mobile terminal based on the communication quality determination criterion 2 is judged whether the communication quality between the two is good or bad. Therefore, the communication quality estimation device 3 can determine the quality of the communication quality by measuring the second base station throughput in the base station 1 without actually measuring the throughput in the mobile terminal 2. When the communication quality estimation device 3 determines that the communication quality is poor, the communication quality estimation device 3 notifies the base station 1 to that effect or displays it on the display unit 33, thereby allowing the wireless communication used by the base station 1 to be performed. Since it becomes possible to take measures such as changing the line, the operator of the base station 1 can improve the communication quality.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment.

DESCRIPTION OF SYMBOLS 1 ... Base station, 2 ... Portable terminal, 3 ... Communication quality estimation apparatus, 31 ... Memory | storage part, 32 ... Communication part, 33 ... Display part, 34 ... Control part

Claims (14)

A communication quality estimation method for estimating communication quality in a radio communication system comprising a base station and a plurality of mobile terminals capable of communicating with the base station,
Generating terminal statistical information including statistical values of throughput of communication trial units measured in a plurality of mobile terminals;
Based on the amount of data received by the base station from the plurality of mobile terminals during a plurality of first measurement periods and the number of mobile terminals that transmitted the data during the plurality of first measurement periods, the mobile terminal 1 Generating first base station statistical information including statistical values of the first base station throughput, which is the throughput per unit;
Generating, based on the first base station statistical information and the terminal statistical information, first estimated statistical information including a statistical value of throughput of a communication trial unit in the base station within the plurality of first measurement periods; ,
A communication quality estimation method comprising: The step of generating the terminal statistical information includes:
Receiving a measured value of throughput in communication trial units and position information indicating the position of each portable terminal from the plurality of portable terminals;
Calculating the average and variance of the measured values for each area to which the position corresponding to the position information belongs;
Generating relationship information indicating a relationship between the average and the variance;
Have
In the step of generating the first estimated statistical information, the first estimated statistical information is generated based on the first base station statistical information and the relationship information.
The communication quality estimation method according to claim 1. The step of generating the first estimated statistical information includes:
Generating a plurality of statistical distribution information based on the average value of the first base station throughput and the relationship information;
Generating a plurality of weighted statistical information by weighting each of the plurality of statistical distribution information based on a probability that the average value has occurred in the plurality of first measurement periods;
Generating the first estimated statistical information by adding each of the plurality of weighted statistical information;
Having
The communication quality estimation method according to claim 2. After generating the first estimated statistical information,
Based on the amount of data received by the base station from the plurality of mobile terminals during a plurality of second measurement periods and the number of mobile terminals that transmitted the data during the plurality of second measurement periods, the mobile terminal 1 Generating second base station statistical information including statistical values of second base station throughput, which is throughput per unit;
Generating, based on the second base station statistical information and the terminal statistical information, second estimated statistical information including a statistical value of throughput of a communication trial unit in the base station within the plurality of second measurement periods; ,
Based on the second estimated statistical information and difference information indicating a difference between a statistical value included in the terminal statistical information and a statistical value included in the first estimated statistical information, Generating third estimated statistical information including statistical values of throughput of communication trial units in the mobile terminal;
Further comprising
The communication quality estimation method according to any one of claims 1 to 3. The step of generating the third estimated statistical information includes:
Calculating a reduction rate of the mode or average value of the throughput of communication trial units included in the terminal statistical information with respect to the mode or average value of throughput of communication trial units included in the first estimated statistical information; ,
Based on the second estimated statistical information and the decrease rate, calculating a mode value or an average value of throughput of communication trial units in the mobile terminal in the plurality of second measurement periods;
Having
The communication quality estimation method according to claim 4. The step of generating the third estimated statistical information includes:
Calculating a throughput dispersion or standard deviation reduction rate of communication trial units included in the terminal statistical information with respect to a throughput distribution or standard deviation of communication trial units included in the first estimated statistical information;
Calculating a variance or standard deviation of throughput of communication trial units in the mobile terminal in the plurality of second measurement periods based on the second estimated statistical information and the decrease rate;
Having
The communication quality estimation method according to claim 4 or 5. After generating the third estimated statistical information,
Obtaining determination criterion information indicating a criterion for determining whether the throughput of the communication trial unit in the mobile terminal is good or bad indicated by the third estimated statistical information;
Based on the determination criterion information, determining whether the throughput of the communication trial unit in the mobile terminal indicated by the third estimated statistical information is acceptable;
According to the determination result of the quality of the third estimated statistical information, the quality of the throughput of the communication trial unit in the base station indicated by the second estimated statistical information used for the estimation of the third estimated statistical information is determined. Steps,
Associating with the second estimated statistical information, a step of storing a communication quality determination criterion indicating the quality of communication quality in a storage unit;
Determining the quality of communication quality between the base station and the mobile terminal based on the communication quality determination criteria;
Further comprising
The communication quality estimation method according to any one of claims 4 to 6. After generating the third estimated statistical information,
Obtaining determination criterion information indicating a criterion for determining whether the throughput of the communication trial unit in the mobile terminal is good or bad indicated by the third estimated statistical information;
Based on the determination criterion information, determining whether the throughput of the communication trial unit in the mobile terminal indicated by the third estimated statistical information is acceptable;
Determining the quality of any of the second base station statistical information and the second base station throughput corresponding to the third estimated statistical information according to the quality judgment result of the third estimated statistical information;
Storing in a storage unit a communication quality criterion indicating whether communication quality is good or low in association with either the second base station statistical information or the second base station throughput;
Determining the quality of communication quality between the base station and the mobile terminal based on the communication quality determination criteria;
Further comprising
The communication quality estimation method according to any one of claims 4 to 6. A communication quality estimation program for estimating communication quality in a wireless communication system comprising a base station and a plurality of mobile terminals capable of communicating with the base station,
On the computer,
Generating terminal statistical information including statistical values of throughput of communication trial units measured in a plurality of mobile terminals;
Based on the amount of data received by the base station from the plurality of mobile terminals during a plurality of first measurement periods and the number of mobile terminals that transmitted the data during the plurality of first measurement periods, the mobile terminal 1 Generating first base station statistical information including statistical values of the first base station throughput, which is the throughput per unit;
Generating, based on the first base station statistical information and the terminal statistical information, first estimated statistical information including a statistical value of throughput of a communication trial unit in the base station within the plurality of first measurement periods; ,
Communication quality estimation program for executing In the computer,
After generating the first estimated statistical information,
Based on the amount of data received by the base station from the plurality of mobile terminals during a plurality of second measurement periods and the number of mobile terminals that transmitted the data during the plurality of second measurement periods, the mobile terminal 1 Generating second base station statistical information including statistical values of second base station throughput, which is throughput per unit;
Generating, based on the second base station statistical information and the terminal statistical information, second estimated statistical information including a statistical value of throughput of a communication trial unit in the base station within the plurality of second measurement periods; ,
Based on the second estimated statistical information and difference information indicating a difference between the terminal statistical information and the first estimated statistical information, the throughput of the communication trial unit in the portable terminal within the plurality of second measurement periods Generating third estimated statistical information including statistical values;
Displaying a statistical value included in at least one of the first estimated statistical information, the second estimated statistical information, and the third estimated statistical information;
For further execution of
The communication quality estimation program according to claim 9. A communication quality estimation device for estimating communication quality in a wireless communication system comprising a base station and a plurality of mobile terminals capable of communicating with the base station,
A first generation unit that generates terminal statistical information including a statistical value of throughput of communication trial units measured in the plurality of mobile terminals;
Based on the amount of data received by the base station from the plurality of mobile terminals during a plurality of first measurement periods and the number of mobile terminals that transmitted the data during the plurality of first measurement periods, the mobile terminal 1 A second generation unit for generating first base station statistical information including a statistical value of the first base station throughput which is a throughput per unit;
Based on the first base station statistical information and the terminal statistical information, a third estimated statistical information including a statistical value of throughput of communication trial units in the base station within the plurality of first measurement periods is generated. A generator,
A communication quality estimation apparatus comprising: Based on the amount of data received by the base station from the plurality of mobile terminals during a plurality of second measurement periods and the number of mobile terminals that transmitted the data during the plurality of second measurement periods, the mobile terminal 1 A fourth generator for calculating second base station statistical information including a statistical value of the second base station throughput that is the throughput per unit;
Based on the second base station statistical information and the terminal statistical information, a second estimated statistical information including a statistical value of throughput of a communication trial unit in the base station in the plurality of second measurement periods is generated. A generator,
Based on the second estimated statistical information and difference information indicating a difference between the terminal statistical information and the first estimated statistical information, the throughput of the communication trial unit in the portable terminal within the plurality of second measurement periods A sixth generator for generating third estimated statistical information including statistical values;
Further comprising
The communication quality estimation apparatus according to claim 11. A wireless communication system comprising a base station, a plurality of mobile terminals that can communicate with the base station, and a communication quality estimation device that estimates the quality of communication between the base station and the plurality of mobile terminals,
A first generation unit that generates terminal statistical information including a statistical value of throughput of communication trial units measured in the plurality of mobile terminals;
Based on the amount of data received by the base station from the plurality of mobile terminals during a plurality of first measurement periods and the number of mobile terminals that transmitted the data during the plurality of first measurement periods, the mobile terminal 1 A second generation unit for generating first base station statistical information including a statistical value of the first base station throughput which is a throughput per unit;
Based on the first base station statistical information and the terminal statistical information, a third estimated statistical information including a statistical value of throughput of communication trial units in the base station within the plurality of first measurement periods is generated. A generator,
A storage unit for storing the terminal statistical information and the first estimated statistical information;
A wireless communication system comprising: Based on the amount of data received by the base station from the plurality of mobile terminals during a plurality of second measurement periods and the number of mobile terminals that transmitted the data during the plurality of second measurement periods, the mobile terminal 1 A fourth generator for calculating second base station statistical information including a statistical value of the second base station throughput that is the throughput per unit;
Based on the second base station statistical information and the terminal statistical information, a second estimated statistical information including a statistical value of throughput of a communication trial unit in the base station in the plurality of second measurement periods is generated. A generator,
Based on the second estimated statistical information and difference information indicating a difference between the terminal statistical information and the first estimated statistical information, the throughput of the communication trial unit in the portable terminal within the plurality of second measurement periods A sixth generator for generating third estimated statistical information including statistical values;
Further comprising
The wireless communication system according to claim 13.

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