JP6888676B2 - Base stations, communication systems, communication control methods, and communication control programs - Google Patents

Description

[Description of related applications]
The present invention is based on the priority claim of Japanese patent application: Japanese Patent Application No. 2017-140155 (filed on July 19, 2017), and all the contents of the application are incorporated in this document by citation. It shall be.
The present invention relates to base stations, communication systems, communication control methods, and communication control programs.

In recent years, with the spread of mobile communication devices such as smartphones, the amount of communication via the mobile communication network has been steadily increasing. However, the amount of packets that can be transmitted from the base station per short time is limited. Therefore, when transmission requests are concentrated on one base station in a congested place such as a terminal station, excessive traffic is often generated with respect to the amount of packets that can be transmitted from the base station. In such a case, the communication quality of the user who uses the smartphone or the like deteriorates.

Therefore, in order to ensure communication quality, for example, a proportional fairness method has been proposed in a wireless communication technology such as LTE (Long Term Evolution) (Non-Patent Document 1). The proportional fairness method is a method in which the priority of allocating wireless resources is set higher for a terminal having a relatively high radio wave quality than the average radio wave quality of the terminal itself. As a result, the proportional fairness method can improve the utilization efficiency of wireless resources and ensure fairness between terminals in terms of communication quality.

Patent Document 1 describes a technique for changing the allocation priority of radio resources to a terminal according to the allowable delay of a packet, which is set according to the performance requirements required for an application program (hereinafter referred to as an application). Has been done. In the technique described in Patent Document 1, the possibility of satisfying the communication quality required for the application can be improved by changing the allocation priority of the wireless resource to the terminal according to the application.

In Patent Document 2, the requirement condition regarding the transmission delay of the packet in which the packet related to the application is stored is acquired from each terminal, and the minimum value of the satisfaction function representing the satisfaction regarding the requirement condition is maximized. , Techniques for allocating radio resources are described.

Japanese Unexamined Patent Publication No. 2005-08612 Japanese Unexamined Patent Publication No. 2010-206316

"Wireless Broadband HSPA + / LTE / SAE Textbook", edited by Takeshi Hattori and Masanobu Fujioka, Impress R & D, Impress Communications

The disclosure of the above prior art documents shall be incorporated into this document by citation. The following analysis was made from the point of view of the present invention.

Generally, in communication using a mobile communication device such as a smartphone, when the waiting time exceeds a predetermined time (for example, 3 seconds), the user cannot wait for the completion of the communication and interrupts the communication. In some cases. Therefore, when the ratio of the number of terminals satisfying a predetermined communication quality decreases, the number of users who are dissatisfied with the communication increases.

In the technique described in Non-Patent Document 1, the base station allocates the radio resource to each terminal in consideration of the utilization efficiency of the radio resource and the fairness of the radio resource allocation to each terminal. However, the technique described in Non-Patent Document 1 does not consider whether or not the communication between each terminal and the base station satisfies a predetermined communication quality. Therefore, when transmission requests are concentrated on one base station in a crowded place or the like, the amount of radio resources allocated to the terminal may be insufficient. In this case, the predetermined communication quality cannot be satisfied, and the number of terminals satisfying the predetermined communication quality decreases.

In the technique described in Patent Document 1, the base station sets the priority of packets according to the allowable delay required for the application. For example, when a plurality of terminals execute the same application, the base station sets the same priority as the packet priority for the plurality of terminals. However, even in the technique described in Patent Document 1, it is not considered whether or not the communication between each terminal and the base station satisfies a predetermined communication quality. Therefore, in the technique described in Patent Document 1, there is a possibility that terminals that execute the same application do not uniformly satisfy a predetermined communication quality. As a result, in the technique described in Patent Document 1, there is a possibility that the number of terminals satisfying a predetermined communication quality cannot be increased.

Further, when the radio wave quality of the terminal is extremely poor, even if the wireless resource is allocated to the terminal, there is a possibility that the predetermined communication quality is not satisfied. However, in the technique described in Patent Document 2, wireless resources are preferentially allocated to the terminal even when the radio wave quality of the terminal is extremely poor. Further, in the technique described in Patent Document 2, wireless resources are allocated even to a terminal satisfying a predetermined communication quality. Therefore, the technique described in Patent Document 2 may not be able to increase the number of terminals that satisfy a predetermined communication quality.

Therefore, an object of the present invention is to provide a base station, a communication system, a communication control method, and a communication control program that contribute to increasing the number of terminals that satisfy a predetermined communication quality.

According to the first aspect of the present invention, a base station is provided. The base station includes a packet transmission / reception unit that wirelessly communicates with two or more terminals.
Further, the base station includes an index calculation unit for calculating a quality index value indicating a probability of satisfying a predetermined communication quality for each terminal.
Further, the base station includes a radio resource allocation unit that allocates radio resources to at least one terminal based on the amount of change in the quality index value corresponding to two or more terminals.

According to the second aspect of the present invention, a communication system is provided. The communication system includes two or more terminals and a base station that communicates with the terminals.
The base station includes a packet transmission / reception unit that wirelessly communicates with two or more terminals.
Further, the base station includes an index calculation unit for calculating a quality index value indicating a probability of satisfying a predetermined communication quality for each terminal.
Further, the base station includes a radio resource allocation unit that allocates radio resources to at least one terminal based on the amount of change in the quality index value corresponding to two or more terminals.

According to the third aspect of the present invention, a communication control method is provided. The communication control method includes a step of performing wireless communication with two or more terminals.
Further, the communication control method includes a step of calculating a quality index value indicating a probability of satisfying a predetermined communication quality for each terminal.
Further, the communication control method includes a step of allocating wireless resources to at least one terminal based on the amount of change in the quality index value corresponding to two or more terminals.
This method is linked to a specific machine called a base station that communicates with two or more terminals.

According to a fourth aspect of the present invention, a program is provided. The program is a program to be executed by a computer that controls a base station. The program causes the computer to execute a process of wirelessly communicating with two or more terminals.
Further, the program causes the computer to execute a process of calculating a quality index value indicating a probability of satisfying a predetermined communication quality for each of the terminals.
Further, the program causes the computer to execute a process of allocating radio resources to at least one terminal based on the amount of change in the quality index value corresponding to two or more terminals.
The program can be recorded on a computer-readable storage medium. The storage medium may be a non-transient such as a semiconductor memory, a hard disk, a magnetic recording medium, or an optical recording medium. The present invention can also be embodied as a computer program product.

According to each viewpoint of the present invention, a base station, a communication system, a communication control method, and a communication control program that contribute to increasing the number of terminals that satisfy a predetermined communication quality are provided.

It is a figure for demonstrating the outline of one Embodiment. It is a block diagram which shows an example of the whole structure of the communication system 1 which concerns on 1st Embodiment. It is a block diagram which shows an example of the internal structure of the base station 20 which concerns on 1st Embodiment. It is a block diagram which shows an example of the hardware composition of the base station 20 which concerns on 1st Embodiment. It is a figure which shows an example of the information which associated communication identification information and communication start time. It is a figure which shows an example of the information which associated the time when a packet was transmitted, and the transmission rate. It is a flowchart which shows an example of the operation of the base station 20 which concerns on 1st Embodiment. It is a flowchart which shows an example of the operation of the base station 20 which concerns on 1st Embodiment. It is a flowchart which shows an example of the operation of the base station 20 which concerns on 1st Embodiment. It is a block diagram which shows an example of the whole structure of the communication system 1a which concerns on 2nd Embodiment. It is a figure which shows an example of communication information. It is a block diagram which shows an example of the internal structure of the base station 21 which concerns on 2nd Embodiment. It is a block diagram which shows an example of the hardware composition of the base station 21 which concerns on 2nd Embodiment. It is a flowchart which shows an example of the operation of the base station 21 which concerns on 2nd Embodiment. It is a flowchart which shows an example of the operation of the base station 21 which concerns on 2nd Embodiment.

First, an outline of one embodiment will be described with reference to FIG. It should be noted that the drawing reference reference numerals added to this outline are added to each element for convenience as an example for assisting understanding, and the description of this outline is not intended to limit anything. Further, the connection line between the blocks in each block diagram includes both bidirectional and unidirectional. Further, although not explicitly stated, an input port and an output port exist at the input end and the output end of each connection line at the connection portion with each connection line of each block. The same applies to the input / output interface.

As described above, a base station that contributes to increasing the number of terminals that satisfy a predetermined communication quality is desired.

Therefore, as an example, the base station 1000 shown in FIG. 1 is provided. The base station 1000 includes a packet transmission / reception unit 1001, an index calculation unit 1002, and a radio resource allocation unit 1003.

The packet transmission / reception unit 1001 wirelessly communicates with two or more terminals.

The index calculation unit 1002 calculates a quality index value indicating the probability of satisfying a predetermined communication quality for each terminal.

The radio resource allocation unit 1003 allocates radio resources to at least one terminal based on the amount of change in the quality index value corresponding to two or more terminals. For example, the radio resource allocation unit 1003 may allocate radio resources to at least one terminal so that the total amount of changes in the quality index values corresponding to two or more terminals is maximized. The amount of change in the quality index value means the amount of change in the quality index value before the allocation of the radio resource and after the allocation of the radio resource. In the following description, the amount of change in the quality index value is also referred to as the quality index difference.

By using the quality index difference, the base station 1000 contributes to prevent, for example, from allocating wireless resources to a terminal whose radio wave quality is extremely poor and which is unlikely to satisfy a predetermined communication quality. .. Further, the base station 1000 contributes to prevent the terminal from allocating excessive radio resources beyond a predetermined communication quality by using the quality index difference. Therefore, the base station 1000 contributes to increasing the number of terminals that satisfy a predetermined communication quality. Further, the base station 1000 contributes to improving the utilization efficiency of wireless resources.

[First Embodiment]
The first embodiment will be described in more detail with reference to the drawings.

FIG. 2 is a block diagram showing an example of the overall configuration of the communication system 1 according to the present embodiment. The communication system 1 according to the present embodiment includes terminals 10 (10-1, 10-2, 10-3), a base station 20, a server device 30, and a network 40. The terminals (10-1, 10-2, 10-3) are referred to as terminals 10 when it is not necessary to distinguish them from each other. Note that FIG. 2 shows three terminals 10, but this does not mean that the number of terminals 10 is limited to three. The communication system 1 according to the present embodiment may be configured to include two or four or more terminals 10.

The terminal 10 is a mobile body having a communication function. The terminal 10 communicates with the server device 30 via the base station 20. The terminal 10 communicates with the base station 20 via wireless communication conforming to mobile communication standards such as W-CDMA (Wideband Code Division Multiple Access) and LTE (Long Term Evolution).

The terminal 10 is configured to include an application program (hereinafter referred to as an application), and acquires information necessary for operating the application from a server device 30 arranged on the Internet.

The base station 20 relays the communication between the terminal 10 and the server device 30. Further, the base station 20 communicates with the server device 30 via the network 40. There are various communication methods for the network 40, but the details are not limited.

Further, the base station 20 performs a process of controlling the allocation of radio resources to the terminal 10 when the packet transmitted from the server device 30 is transferred to the terminal 10.

For example, in LTE, the base station 20 determines to which terminal 10 the RB (Resource Block) is assigned. Then, the base station 20 transmits a packet to the terminal 10 for each RB. In the following description, RB will be described as an example as a unit of radio resources allocated to the terminal 10 by the base station 20. However, this does not mean that the unit of radio resources allocated to the terminal 10 by the base station 20 is limited to RB.

The server device 30 transmits a packet to the terminal 10. For example, the server device 30 may be an HTTP (Hypertext Transfer Protocol) server. For example, when the server device 30 is an HTTP server, the server device 30 receives a GET request from the terminal 10 and returns the content described in the GET request to the terminal 10 as a response to the received GET request. In the following description, a case where the server device 30 is an HTTP server will be described as an example. However, this does not mean that the server device 30 is limited to the HTTP server. For example, the server device 30 may be an HTTPS (Hypertext Transfer Protocol Secure) server, an FTP (File Transfer Protocol) server, or a server that communicates using another protocol.

FIG. 3 is a block diagram showing an example of the internal configuration of the base station 20 according to the present embodiment. The base station 20 includes a packet transmission / reception unit 201, a residual communication amount calculation unit 202, a communication time calculation unit 203, a transmission rate calculation unit 204, a terminal number calculation unit 205, an index calculation unit 206, and a radio resource allocation unit. It is configured to include 207.

FIG. 4 is a block diagram showing an example of the hardware configuration of the base station 20 according to the present embodiment. Note that FIG. 4 is an example of the hardware configuration of the base station 20, and does not mean that the hardware configuration of the base station 20 is limited to the configuration shown in FIG.

The packet transmission / reception unit 201 performs wireless communication with two or more terminals 10. As shown in FIG. 4, the packet transmission / reception unit 201 may be realized by using the communication interface 2011, the processor 2012, and the memory 2013.

Specifically, the packet transmission / reception unit 201 receives a packet from the terminal 10 via wireless communication and transfers the packet to the server device 30. Further, the packet transmission / reception unit 201 receives a packet from the server device 30 via wireless communication and transfers the packet to the terminal 10.

When transmitting a packet to the terminal 10, the packet transmission / reception unit 201 transfers the packet using the radio resource allocated by the radio resource allocation unit 207. For example, when the radio resource allocation unit 207 determines to allocate the radio resource (RB) to the terminal 10-1, the packet transmission / reception unit 201 uses the radio resource (RB) to packet to the terminal 10-1. To send. Details of the radio resource allocation unit 207 will be described later.

The residual communication amount calculation unit 202 calculates the amount of packets that are scheduled to be transmitted to the terminal 10 and have not been transmitted as the residual communication amount. As shown in FIG. 4, the residual communication amount calculation unit 202 may be realized by using the communication interface 2021, the processor 2022, and the memory 2023.

The residual communication amount calculation unit 202 notifies the index calculation unit 206 of the calculated residual communication amount. Further, the residual communication amount calculation unit 202 stores the calculated residual communication amount in the memory 2023 of the residual communication amount calculation unit 202. Here, the residual communication amount means the amount of packets (packet size) that are scheduled to be transmitted from the base station 20 to the terminal 10 and have not been transmitted.

The residual communication amount calculation unit 202 may calculate the residual communication amount based on the HTTP header included in the packet transmitted from the server device 30.

For example, it is assumed that the residual communication amount calculation unit 202 calculates the residual communication amount corresponding to the terminal 10-1. In that case, the residual communication amount calculation unit 202 refers to the Content-Length field of the HTTP response header included in the packet transmitted from the server device 30 to the terminal 10-1. Here, in the Content-Length field of the HTTP response header included in the packet transmitted from the server device 30 to the terminal 10-1, the amount of packets scheduled to be transmitted from the server device 30 to the terminal 10-1 is described. .. Therefore, the residual communication amount calculation unit 202 may calculate the residual communication amount based on the value described in the Content-Dimension field.

Each time the packet transmission / reception unit 201 transmits a packet to the terminal 10, the residual communication amount calculation unit 202 subtracts the packet amount transmitted by the packet transmission / reception unit 201 to the terminal 10 from the residual communication amount to obtain a residual amount. Update traffic. In the following description, the amount of packets transmitted by the packet transmission / reception unit 201 to the terminal 10 is referred to as a transmission packet amount.

Further, it is assumed that the base station 20 receives the packet including the HTTP response header addressed to the terminal 10 before the residual communication amount becomes zero. In that case, the residual communication amount calculation unit 202 refers to the Content-Length field of the HTTP response header, and integrates the value described in the Content-Length field into the residual communication amount corresponding to the terminal 10. As a result, even when the base station 20 transmits a packet using two or more HTTP sessions, the residual communication amount calculation unit 202 can calculate the correct residual communication amount.

Further, the communication between the terminal 10 and the server device 30 is encrypted communication, and it may be difficult for the residual communication amount calculation unit 202 to obtain the residual communication amount corresponding to the terminal 10. In that case, the residual communication amount calculation unit 202 may calculate the predicted value of the residual communication amount based on the distribution of the past communication amount. For example, the residual communication amount calculation unit 202 may calculate the probability distribution of the residual communication amount based on the distribution of the past communication amount corresponding to the terminal 10 and the transmission packet amount transmitted after the start of communication. Then, the residual communication amount calculation unit 202 may calculate the predicted value of the residual communication amount based on the probability distribution of the residual communication amount. Then, the residual communication amount calculation unit 202 may notify the index calculation unit 206 of the predicted value of the residual communication amount.

When the residual communication amount calculation unit 202 calculates the predicted value of the residual communication amount, it is preferable that there is a record of communication between the target terminal 10 and the server device 30 for a predetermined period. Therefore, the residual communication amount calculation unit 202 may determine whether or not the predicted value of the residual communication amount can be calculated based on the number of communications between the server device 30 and the base station 20. When the number of communications between the server device 30 and the base station 20 exceeds a predetermined number of times, the residual communication amount calculation unit 202 determines that the predicted value of the residual communication amount can be calculated. On the other hand, when the number of communications between the server device 30 and the base station 20 is equal to or less than a predetermined number of times, the residual communication amount calculation unit 202 determines that the predicted value of the residual communication amount cannot be calculated.

The communication time calculation unit 203 calculates the time elapsed since the start of communication with the terminal 10 as the communication time. As shown in FIG. 4, the communication time calculation unit 203 may be realized by using the communication interface 2031, the processor 2032, and the memory 2033.

Specifically, the communication time calculation unit 203 calculates the time elapsed since the base station 20 starts transmitting the packet to the terminal 10 as the communication time. Further, the communication time calculation unit 203 notifies the index calculation unit 206 of the calculated communication time.

Further, the communication time calculation unit 203 calculates the difference between the current time and the communication start time between the terminal 10 and the base station 20 as the communication time between the terminal 10 and the base station 20.

For example, the communication time calculation unit 203 may determine the time when the base station 20 starts transmitting a packet addressed to the terminal 10 as the communication start time between the terminal 10 and the base station 20. Specifically, the communication time calculation unit 203 determines the time when the residual communication amount of the terminal 10 changes from 0 to a value larger than 0 as the communication start time between the terminal 10 and the base station 20. May be good.

Alternatively, it is assumed that the residual communication amount of the terminal 10 continues to be 0 for a predetermined time (for example, 300 milliseconds), and then the residual communication amount becomes larger than 0. In that case, the communication time calculation unit 203 may determine the time when the residual communication amount becomes larger than 0 as the communication start time.

Further, it is assumed that the residual communication amount of the terminal 10 becomes larger than 0 after the state in which the residual communication amount is 0 continues for a predetermined time or less. The communication time calculation unit 203 may determine the communication start time corresponding to the immediately preceding communication as the communication start time of the new communication. There are various methods for determining the communication start time, but the details are not limited.

For example, assume that the server device 30 provides a Web page. Then, it is assumed that the terminal 10 accesses the Web page provided by the server device 30. In that case, the terminal 10 downloads the HTML (Hypertext Markup Language) format packet from the server device 30, and starts downloading the content related to the packet based on the content of the downloaded packet. In that case, after the terminal 10 finishes downloading the HTML format packet and before downloading the related content, the residual communication amount of the terminal 10 becomes 0.

Here, it is assumed that the time from the end of the download of the HTML format packet to the start of the download of the related content by the terminal 10 is not more than a predetermined time. In that case, the communication time calculation unit 203 may determine the communication start time of the process of downloading the HTML format packet (communication process) as the communication start time of the process of downloading the related content (communication process). By doing so, the base station 20 assumes that the process of downloading HTML format packets (communication process) and the process of downloading related contents (communication process) are a series of processes (a series of communication processes). You may judge.

The communication time calculation unit 203 stores the determined communication start time in the memory 2033 of the communication time calculation unit 203. The communication time calculation unit 203 may store information in which information for identifying the terminal 10 (hereinafter referred to as terminal identification information) and communication start time are associated with each other in the memory 2033 of the communication time calculation unit 203. For example, the communication time calculation unit 203 may store the information in which the terminal identification information and the communication start time are associated with each other in the memory 2033 of the communication time calculation unit 203 in a table format.

The terminal identification information may be the MAC address, IP address, RNTI (Radio Network Temporary Identifier), or the like of the terminal 10. That is, the communication time calculation unit 203 may store the information in which the MAC address of the terminal 10 and the communication start time are associated with each other in the memory 2033 of the communication time calculation unit 203.

Alternatively, the communication time calculation unit 203 may store information in which the IP address of the terminal 10 and the communication start time are associated with each other in the memory 2033 of the communication time calculation unit 203. Alternatively, the communication time calculation unit 203 may store the information in which the RNTI of the terminal 10 and the communication start time are associated with each other in the memory 2033 of the communication time calculation unit 203.

FIG. 5 is a diagram showing an example of information in which the communication identification information and the communication start time are associated with each other. For example, in the first line of FIG. 5 (the title line is the 0th line), the communication start time between the terminal 10 and the base station 20 corresponding to the terminal identification information “1” is 13:11:34.319 seconds. ("13: 11: 34.319"). In the second line of FIG. 5, the communication start time between the terminal 10 and the base station 20 corresponding to the terminal identification information “2” is 13:11: 12.984 seconds (“13: 11: 12.984”). Indicates that there is. In the third line of FIG. 5, the communication start time between the terminal 10 and the base station 20 corresponding to the terminal identification information “3” is 13:10:52.532 seconds (“13:10: 52.532”). Indicates that there is.

For example, assume that the current time is 13:11:35.758 seconds ("13: 11: 35.758"). In that case, with respect to the terminal 10 corresponding to the terminal identification information "1" shown in FIG. 5, the communication time calculation unit 203 performs 1.439 seconds (= 13:11:35.758 seconds-13:11:34.319 seconds). ) Is calculated as the communication time.

The transmission rate calculation unit 204 calculates the amount of packets that can be transmitted per unit amount of wireless resources to the terminal 10 as the transmission rate. As shown in FIG. 4, the transmission rate calculation unit 204 may be realized by using the communication interface 2041, the processor 2042, and the memory 2043.

For example, in LTE, the transmission rate calculation unit 204 calculates the amount of packets that can be transmitted per RB to the terminal 10 as the transmission rate corresponding to the terminal 10. Hereinafter, the unit amount that serves as a reference for wireless resources is referred to as a unit wireless resource. In addition, hereinafter, the number of radio resources based on the unit radio resource is referred to as the number of radio resources.

The transmission rate calculation unit 204 notifies the index calculation unit 206 of the calculated transmission rate. The packet transmission / reception unit 201 transmits a packet to the terminal 10 based on the transmission rate calculated by the transmission rate calculation unit 204.

In wireless communication, a packet that can be transmitted to the terminal 10 by the base station 20 using a unit wireless resource according to the reception quality when the terminal 10 receives a radio wave (hereinafter referred to as the received radio wave quality). The amount is different. That is, in wireless communication, the transmission rate corresponding to the terminal 10 differs depending on the received radio wave quality of the terminal 10.

Hereinafter, an example of a process in which the transmission rate calculation unit 204 calculates the transmission rate will be described.

The transmission rate calculation unit 204 may calculate the transmission rate for each terminal 10 based on the actual value of the past transmission rate. Specifically, the transmission rate r at the current time tk may be calculated for each terminal 10 using the following equation _1. Here, in the following equation (1), _{r i} denote the transmission rate at time _{t i (i, k, n} : _{integer, i <n <k, t} i <t k, t i-1 < t _i). That, r _i denote the past transmission rate. Further, in the following equation 1, n represents an interval (for example, n = 3) in which the moving average is performed.

[Number 1]

That is, the transmission rate calculation section 204, as shown in Formula 1 above, a moving average of past transmission rate may be calculated as the transmission rate r of the current time t _k. For example, a time _{t i,} the time difference between the time _{t i-1,} may be 1 ms (millisecond).

The transmission rate calculation unit 204 stores information in which the time when the packet is transmitted and the transmission rate when the packet is transmitted are associated with each other in the memory 2043 of the transmission rate calculation unit 204. Specifically, the transmission rate calculation unit 204 stores the information in which the time when the packet is transmitted and the transmission rate at the time of transmitting the packet are associated with each other in the memory 2043 of the transmission rate calculation unit 204 in a table format. You may.

FIG. 6 is a diagram showing an example of information in which the time when the packet is transmitted and the transmission rate when the packet is transmitted are associated with each other. Specifically, FIG. 6 shows that packets are transmitted at _{time ti-1} , time ti _-2 , and time ti _-3 (i: integer, ti _-3 <ti _-2 <ti _-1). Indicates the transmission rate at the time of. For example, in the first line of FIG. 6 (the title line is the 0th line), the transmission rate when the base station 20 transmits a packet to the terminal 10 at _{time ti-1 is 30 bytes / RB.} Indicates that there was.

The packet transmission rate from the base station 20 to the terminal 10 changes from moment to moment according to the fluctuation of the received radio wave quality of the terminal 10. However, transmission rate calculation unit 204, based on the moving average of past transmission rate, by calculating the transmission rate at the current time, can calculate an appropriate transmission rate at the current time t _i.

Alternatively, the transmission rate calculation unit 204 may calculate the transmission rate at the current time based on the exponential moving average of the past transmission rates.

Alternatively, the transmission rate calculation unit 204 may calculate the transmission rate at the current time based on the transmission rate in the latest communication between the terminal 10 and the base station 20.

Alternatively, when the base station 20 receives information indicating the received radio wave quality of the terminal 10 (hereinafter referred to as a received radio wave quality index), the transmission rate calculation unit 204 determines the current time based on the received received radio wave quality index. The transmission rate of may be calculated. For example, when the base station receives the CQI (Channel Quality Indicator) from the terminal 10, the transmission rate calculation unit 204 may calculate the transmission rate corresponding to the terminal 10 based on the received CQI. The above transmission rate calculation method is an example, and the purpose is not to limit the transmission rate calculation method to the above method.

The terminal number calculation unit 205 calculates the number of terminals (hereinafter, referred to as the number of communication terminals) that are communicating with the base station 20. As shown in FIG. 4, the terminal number calculation unit 205 may be realized by using the communication interface 2051, the processor 2052, and the memory 2053.

The terminal number calculation unit 205 notifies the index calculation unit 206 of the calculated number of communication terminals. The terminal number calculation unit 205 stores the calculated number of communication terminals in the memory 2053 of the terminal number calculation unit 205.

For example, the terminal number calculation unit 205 may refer to the packet held by the packet transmission / reception unit 201 and calculate the number of communication terminals based on the number of terminals corresponding to the destination and / or the source of the packet. ..

Alternatively, the terminal number calculation unit 205 may calculate the number of communication terminals by using the residual communication amount for each terminal 10 calculated by the residual communication amount calculation unit 202. Specifically, the terminal number calculation unit 205 may calculate the number of terminals whose residual communication amount exceeds 0 as the number of communication terminals.

Further, the terminal number calculation unit 205 may calculate an average value for a predetermined number of times in the past with respect to the number of communication terminals calculated by using the above method, and determine the calculated average value as the number of communication terminals. .. The number of communication terminals changes from moment to moment. Therefore, the terminal number calculation unit 205 can calculate the number of communication terminals by suppressing the fluctuation of the number of communication terminals by taking the average.

The index calculation unit 206 calculates a quality index value indicating the probability of satisfying a predetermined communication quality for each terminal 10. As shown in FIG. 4, the index calculation unit 206 may be realized by using the communication interface 2061, the processor 2062, and the memory 2063.

Specifically, the index calculation unit 206 calculates the quality index value corresponding to each terminal 10 based on the residual communication amount, the communication time, the transmission rate, and the number of communication terminals corresponding to each terminal 10. To do.

As described above, the residual communication amount calculation unit 202 notifies the index calculation unit 206 of the calculated residual communication amount. The communication time calculation unit 203 notifies the index calculation unit 206 of the calculated communication time. The transmission rate calculation unit 204 notifies the index calculation unit 206 of the calculated transmission rate. The terminal number calculation unit 205 notifies the index calculation unit 206 of the calculated number of communication terminals. The index calculation unit 206 calculates the quality index value based on the notified residual communication amount, the communication time, the transmission rate, and the number of communication terminals.

Further, as described above, the quality index value indicates the probability of satisfying a predetermined communication quality. That is, the quality index value indicates that the larger the value, the higher the possibility that the communication between the terminal 10 and the base station 20 satisfies a predetermined communication quality. In the following description, the quality index value shall be a value between 0 and 1.

For example, when the communication between the terminal 10 and the base station 20 is completed within a predetermined time (for example, within 3 seconds), the communication between the terminal 10 and the base station 20 may satisfy the predetermined communication quality. Here, if the base station 20 can transmit packets corresponding to the remaining communication amount to the terminal 10 within the time allowed for communication between the terminal 10 and the base station 20, the terminal 10 and the base can be transmitted within a predetermined time. It is assumed that the communication between the stations 20 is terminated.

On the other hand, if the base station 20 is not capable of transmitting packets corresponding to the remaining communication amount to the terminal 10 within the time allowed for communication between the terminal 10 and the base station 20, the terminal 10 and the base station are within a predetermined time. It is assumed that the communication between 20 cannot be completed. In the following description, the time that allows communication between the terminal 10 and the base station 20 is referred to as the residual communication time corresponding to the terminal 10.

Alternatively, when the MOS (Mean Opinion Score) estimated from the transmission rate, communication delay, or the like exceeds a predetermined threshold value, the communication between the terminal 10 and the base station 20 may satisfy the predetermined communication quality. The index calculation unit 206 can evaluate the communication quality that reflects the user's experience by determining whether or not the communication between the terminal 10 and the base station 20 satisfies a predetermined communication quality based on the MOS. .. It should be noted that this is an example of a communication quality determination method, and does not mean to limit the communication quality determination method.

Even if the base station 20 allocates wireless resources to the terminal 10 whose received radio wave quality is extremely poor, the communication quality between the terminal 10 and the base station 20 does not improve. That is, with respect to the terminal 10 whose received radio wave quality is extremely poor, there is a possibility that the communication between the terminal 10 and the base station 20 may not satisfy the predetermined communication quality. Therefore, the index calculation unit 206 so that the smaller the possibility of satisfying the predetermined communication quality, the smaller the increase amount of the quality index value corresponding to the terminal 10 when the wireless resource is allocated to the terminal 10. , Calculate the quality index value.

Further, when the communication between the terminal 10 and the base station 20 is sufficiently likely to satisfy a predetermined communication quality, the base station 20 and the terminal 10 may increase or decrease the radio resources allocated to the terminal 10. The amount of change in the possibility that the communication between the base stations 20 satisfies a predetermined communication quality is small. Therefore, the index calculation unit 206 so that the smaller the possibility of satisfying the predetermined communication quality, the smaller the increase amount of the quality index value corresponding to the terminal 10 when the wireless resource is allocated to the terminal 10. , Calculate the quality index value.

Hereinafter, the method of calculating the quality index value will be described in detail. In the following description, when the communication between the terminal 10 and the base station 20 is completed within a predetermined time (for example, within 3 seconds), the communication between the terminal 10 and the base station 20 satisfies the predetermined communication quality. It shall be. That is, in the following description, when the communication between the base station 20 and the terminal 10 is started and the communication is completed by a predetermined deadline (hereinafter referred to as the communication end deadline), the communication between the terminal 10 and the base station 20 is completed. It is assumed that the communication meets the predetermined communication quality.

The index calculation unit 206 calculates the remaining communication time. Specifically, the index calculation unit 206 calculates the difference between the time after the communication time has elapsed from the communication start time and the communication end deadline as the residual communication time. The index calculation unit 206 shall calculate the residual communication time for each terminal 10.

The index calculation unit 206 calculates the amount of packets d that can be transmitted from the base station 20 to the terminal 10 within the remaining communication time.

_{For example, the index calculation unit 206 calculates the amount of packets dk} that can be transmitted from the base station 20 to the terminal 10-k (a natural number of k: 1 or more) within the remaining communication time. In that case, index calculating section 206, a radio resource number N _R allocated to the remaining communication time, and the transmission rate R when transmitting a packet to the terminal 10-k, the number of terminals N _T that connects to the base station 20 _{Based on the above, the amount of packets dk} that can be transmitted to the terminal 10-k within the remaining communication time is calculated.

Specifically, the index calculator 206 calculates the amount of transmittable packets within the remaining communication time _{d k = N R R / N} T to the terminal 10-k.

Further, the index calculation unit 206 calculates the number of surplus radio resources. Specifically, by using a number of 2 or less, index calculation unit 206 calculates a surplus radio resources the number N _S corresponding to the terminal 10-k.

[Number 2]

Excess radio resources the number N _S, of the transmittable packet amount d _k in remaining communication time, the number of excess radio resources to the remainder traffic D.

Regard the terminal 10-k, the more excess radio resources number N _S is large, the up communication expiration, the communication between the terminal 10-k and the base station 20 is improved may have ended. Therefore, the index calculation unit 206, as excess radio resources the number N _S corresponding to the terminal 10-k is large, as quality indicator value corresponding to the terminal 10-k is increased, and calculates the quality index value.

However, when the number of surplus radio resources _NS is excessively large, it is possible that the communication between the terminal 10-k and the base station 20 has been completed by the communication end deadline even if the number of surplus radio resources _{NS is different.} Sex does not change significantly (ie, saturates). Similarly, when the number of surplus radio resources _NS is excessively small, even if the number of surplus radio resources _NS is different, the communication between the terminal 10-k and the base station 20 is completed by the communication end deadline. The possibilities do not change significantly (ie, saturate). Therefore, when the surplus radio resources number N _S is outside the predetermined range, the index calculation unit 206, a predetermined value may be calculated as a quality indicator value.

For example, the index calculation unit 206 uses the number 3 below, may be calculated quality index value I _k corresponding to the terminal 10-k. In the following equation 3, C is a constant.

[Number 3]

The above number 3 is an example, and does not mean to limit the calculation method of the quality index value. For example, the index calculation unit 206 may calculate the quality index value by using the sigmoid function, the tanh function, or the like.

The radio resource allocation unit 207 allocates radio resources to the terminal 10 based on the quality index value for each terminal 10 calculated by the index calculation unit 206.

Specifically, the index calculation unit 206 calculates the quality index difference when the radio resources are allocated to each terminal 10. _{For example, the index calculation unit 206 may calculate the quality index difference ΔI k} corresponding to the terminal 10-k (a natural number of k: 1 or more) by using the following equation 4. In the following equation 4, C is a constant. The following number 4 is an example, and does not mean to limit the calculation method of the quality index difference.
[Number 4]

The radio resource allocation unit 207 allocates radio resources to at least one terminal 10 based on the quality index difference corresponding to two or more terminals 10. As shown in FIG. 4, the radio resource allocation unit 207 may be realized by using the communication interface 2071, the processor 2072, and the memory 2073.

Specifically, the radio resource allocation unit 207 determines to allocate the radio resource to the terminal 10 whose quality index difference satisfies a predetermined condition (hereinafter, referred to as a first condition). Then, the radio resource allocation unit 207 transmits a packet to the terminal 10 to which the radio resource is allocated.

For example, the radio resource allocation unit 207 may decide to allocate the radio resource to the terminal 10 having the relatively largest quality index difference among the two or more target terminals. It should be noted that this is an example of the criteria for determining the terminal 10 to which the wireless resource is allocated, and does not mean to limit the criteria for determining the terminal 10 to which the wireless resource is allocated. The radio resource allocation unit 207 may determine the terminal 10 to which the radio resource is allocated based on other criteria as long as the quality index difference is used.

Further, it is assumed that the quality index difference corresponding to two or more terminals 10 satisfies the first condition. In that case, the radio resource allocation unit 207 may decide to allocate the radio resource to the terminal 10 that satisfies the second condition among the terminals 10 that satisfy the first condition.

For example, the radio resource allocation unit 207 may decide to allocate the radio resource to the terminal 10 having the relatively oldest communication start time among the terminals 10 satisfying the first condition. As a result, the time until the communication is completed can be leveled.

Here, it is assumed that the index calculation unit 206 calculates that the quality index difference corresponding to the terminal 10-1 is 1. Further, it is assumed that the index calculation unit 206 calculates that the quality index difference corresponding to the terminals 10-2 and 10-3 is 0. Then, it is assumed that the radio resource allocation unit 207 allocates the radio resource to the terminal 10 having the relatively largest quality index difference among the two or more target terminals. In that case, the radio resource allocation unit 207 decides to allocate the radio resource to the terminal 10-1.

It is assumed that the base station 20 calculates the expected value of the quality index value based on the predicted value of the residual communication amount when the communication between the terminal 10 and the server device 30 is encrypted communication. In that case, the base station 20 may determine the terminal 10 to which the radio resource is allocated by using the expected value of the calculated quality index value. As a result, the base station 20 contributes to increasing the number of terminals that satisfy a predetermined communication quality even when the communication between the terminal 10 and the server device 30 is encrypted communication.

Further, when the communication amount calculation unit cannot calculate the predicted value of the residual communication amount, the radio resource allocation unit 207 may preferentially allocate the radio resource to the terminal 10 which cannot calculate the predicted value of the residual communication amount. The radio resource allocation unit 207 preferentially allocates the radio resources to the terminal 10 for which the predicted value of the residual communication amount cannot be calculated, so that the base station 20 can collect the information necessary for the prediction at an early stage. become.

Next, the operation of the base station 20 according to the present embodiment will be described with reference to FIGS. 7, 8 and 9.

FIG. 7 is a flowchart showing an example of processing when the base station 20 receives a packet addressed to the terminal 10 from the server device 30. In the following description, a case where the base station 20 receives a packet addressed to the terminal 10-1 from the server device 30 will be described as an example.

In step S1001, the packet transmission / reception unit 201 receives a packet from the server device 30. Specifically, the packet transmission / reception unit 201 receives a packet addressed to the terminal 10-1 from the server device 30.

In step S1002, the residual communication amount calculation unit 202 determines whether or not the received packet includes the HTTP header. When the received packet includes the HTTP header (Yes branch in step S1002), the process proceeds to step S1003. On the other hand, when the received packet does not include the HTTP header (No branch in step S1002), the process proceeds to step S1006.

In step S1003, the residual communication amount calculation unit 202 updates the residual communication amount corresponding to the terminal 10-1 of the destination of the received packet (step S1003). Specifically, the residual communication amount calculation unit 202 refers to the Content-Length field of the HTTP header included in the received packet. Then, the residual communication amount calculation unit 202 integrates the value of the referenced Content-Length field into the residual communication amount of the terminal 10-1 stored in the residual communication amount calculation unit 202.

For example, it is assumed that the remaining communication amount of the terminal 10-1 is 1300. Further, it is assumed that the value of the Content-Length field of the HTTP header included in the received packet is 5600. In that case, the residual communication amount calculation unit 202 calculates that the residual communication amount of the terminal 10-1 is 6900 (= 1300 + 5600).

In step S1004, the residual communication amount calculation unit 202 determines whether or not the residual communication amount corresponding to the terminal 10-1 of the destination of the received packet is 0. When the residual communication amount corresponding to the terminal 10-1 of the destination of the received packet is 0 (Yes branch in step S1004), the process proceeds to step S1005. On the other hand, when the residual communication amount is not 0 (No branch in step S1004) corresponding to the terminal 10-1 of the destination of the received packet, the process proceeds to step S1006.

In step S1005, the communication time calculation unit 203 updates the communication start time between the destination terminal 10-1 and the base station 20 of the received packet. Specifically, the communication time calculation unit 203 determines the current time as the communication start time.

For example, assume that the current time is 13:11:34.319 seconds. In that case, the communication time calculation unit 203 determines the communication start time between the terminal 10-1 and the base station 20 at 13:11:34.319. Then, the communication time calculation unit 203 stores the determined communication start time in the memory 2033 of the communication time calculation unit 203. For example, the communication time calculation unit 203 may store the information in which the terminal identification information of the terminal 10-1 and the communication start time are associated with each other in the memory 2033 of the communication time calculation unit 203.

In step S1006, the communication time calculation unit 203 passes the received packet to the packet transmission / reception unit 201. The packet transmission / reception unit 201 holds the received packet to the terminal 10-1 until the radio resource is allocated.

FIG. 8 is a flowchart showing an example of processing when the base station 20 transmits the received packet to the terminal 10.

In step S1101, the radio resource allocation unit 207 determines the terminal 10 to which the radio resource is allocated. The details of the process of determining the terminal 10 to which the wireless resource is allocated will be described later. In the following description, a case where the radio resource allocation unit 207 determines the terminal 10-1 as a target for allocating the radio resource will be described as an example.

In step S1102, the radio resource allocation unit 207 allocates the radio resource to the determined terminal 10. Specifically, the radio resource allocation unit 207 allocates radio resources to the terminal 10-1.

In step S1103, the packet transmission / reception unit 201 transmits a packet to the determined terminal 10-1 via wireless communication. When the packet transmission / reception unit 201 transmits a packet to the terminal 10-1, the packet transmission / reception unit 201 notifies the residual communication amount calculation unit 202 of the transmission packet amount to the terminal 10-1.

In step S1104, the residual communication amount calculation unit 202 updates the residual communication amount corresponding to the determined terminal 10-1. Specifically, the residual communication amount calculation unit 202 calculates the residual communication amount of the terminal 10-1 based on the transmission packet amount for the terminal 10-1. For example, the residual communication amount calculation unit 202 calculates a value obtained by subtracting the transmission packet amount from the residual communication amount before the packet is transmitted as the residual communication amount after the packet is transmitted.

Further, the residual communication amount calculation unit 202 notifies the transmission rate calculation unit 204 of the number of radio resources allocated to the terminal 10-1 and the transmission packet amount.

Here, it is assumed that the residual communication amount of the terminal 10-1 is 5630 bytes. Further, it is assumed that the amount of transmitted packets to the terminal 10-1 is 1500 bytes. In that case, the residual communication amount calculation unit 202 sets the packet as the value obtained by subtracting the transmission packet amount (that is, 1500 bytes) from the residual communication amount (that is, 5630 bytes) before transmitting the packet (that is, 4130 bytes). Calculated as the residual communication volume after transmission.

In step S1105, the transmission rate calculation unit 204 updates the transmission rate corresponding to the determined terminal 10-1. Specifically, the transmission rate calculation unit 204 updates the transmission rate corresponding to the terminal 10-1 based on the radio resource allocated to the terminal 10-1 and the amount of transmission packets for the terminal 10-1. For example, the transmission rate calculation unit 204 calculates the value obtained by dividing the amount of transmission packets by the number of radio resources allocated to the terminal 10-1 as the transmission rate corresponding to the terminal 10-1.

Here, it is assumed that the number of radio resources allocated to the terminal 10-1 is 50 when the unit radio resource is RB. That is, it is assumed that the number of RBs assigned to the terminal 10-1 as a radio resource is 50. In that case, the transmission rate calculation unit 204 divides the transmission packet amount (that is, 1500 bytes) by the number of radio resources allocated to the terminal 10-1 (that is, the number of RBs is 50) (1500/50 = 30). ) Is calculated as the transmission rate corresponding to the terminal 10-1.

FIG. 9 is a flowchart showing an example of the process of calculating the quality index value. It is assumed that the base station 20 executes the process shown in FIG. 9 every time the radio resource is allocated to the terminal 10. For example, suppose that the base station 20 and the terminal 10 communicate with each other via LTE. In that case, the base station 20 shall execute the process shown in FIG. 9 for each TTI (Transmission Time Interval).

In step S1201, the packet transmission / reception unit 201 identifies the terminal 10 corresponding to the destination of the untransmitted packet as the target terminal. That is, the packet transmission / reception unit 201 determines the terminal 10 corresponding to the destination of the packet among the held packets as the target terminal. Here, the packet transmission / reception unit 201 may determine one or more terminals 10 as target terminals. In the following description, a case where the packet transmission / reception unit 201 specifies terminals 10-1, 10-2, and 10-3 as target terminals will be described as an example.

In step S1202, the index calculation unit 206 determines whether or not the quality index difference has been calculated for all the target terminals. Specifically, the index calculation unit 206 determines whether or not the quality index difference of each target terminal is calculated when the radio resources are allocated to the target terminals for all the target terminals.

When the index calculation unit 206 calculates the quality index difference for all the target terminals (Yes branch in step S1202), the process proceeds to step S1209. On the other hand, when the index calculation unit 206 does not calculate the quality index difference for all the target terminals (No branch in step S1202), the transition to step S1203 occurs.

In step S1203, the index calculation unit 206 selects the target terminal 10 for calculating the quality index value. Specifically, the index calculation unit 206 selects one terminal 10 from one or two or more terminals 10 for which the quality index value has not been calculated. In the following description, the index calculation unit 206 exemplifies the case where the terminal 10-1 is selected.

In step S1204, the residual communication amount calculation unit 202 calculates the residual communication amount corresponding to the selected terminal 10-1. Specifically, the residual communication amount calculation unit 202 calculates the residual communication amount corresponding to the terminal 10-1. Then, the residual communication amount calculation unit 202 notifies the index calculation unit 206 of the calculated residual communication amount.

In step S1205, the communication time calculation unit 203 calculates the communication time corresponding to the selected terminal 10-1. Specifically, the communication time calculation unit 203 acquires the communication start time between the terminal 10-1 and the base station 20 from the memory 2033 of the communication time calculation unit 203. Further, the communication time calculation unit 203 acquires the current time. The communication time calculation unit 203 calculates the difference between the acquired current time and the communication start time as the communication time corresponding to the terminal 10-1. Then, the communication time calculation unit 203 notifies the index calculation unit 206 of the calculated communication time.

For example, assume that the communication start time between the terminal 10-1 and the base station 20 is 13:11:34.319 seconds. Further, it is assumed that the current time is 13:11:35.657 seconds. In that case, the communication time calculation unit 203 sets the difference between the acquired current time and the communication start time (13:11:35.657 seconds-13:11:34.319 seconds = 1.338 seconds) at the terminal 10-. Calculated as the communication time corresponding to 1.

In step S1206, the transmission rate calculation unit 204 calculates the transmission rate corresponding to the selected terminal. Specifically, the transmission rate calculation unit 204 extracts the actual value of the past transmission rate corresponding to the terminal 10-1 from the memory 2043 of the transmission rate calculation unit 204. The transmission rate calculation unit 204 calculates the transmission rate at the current time based on the actual value of the past transmission rate corresponding to the terminal 10-1. Then, the transmission rate calculation unit 204 notifies the index calculation unit 206 of the calculated transmission rate.

In step S1207, the terminal number calculation unit 205 calculates the number of terminals communicating with the base station as the number of communication terminals. Then, the terminal number calculation unit 205 notifies the index calculation unit 206 of the calculated number of communication terminals.

In step S1208, the index calculation unit 206 calculates the quality index difference corresponding to the selected terminal 10-1. Specifically, the index calculation unit 206 calculates the number of surplus radio resources corresponding to the terminal 10-1. Then, the index calculation unit 206 calculates the quality index value using the calculated number of surplus radio resources. Then, the index calculation unit 206 calculates the quality index difference corresponding to the terminal 10-1. Then, the process returns to step S1202 and the process is continued.

For example, it is assumed that the residual communication amount calculation unit 202 calculates that the residual communication amount corresponding to the terminal 10-1 is 411 kilobytes. Further, it is assumed that the communication time calculation unit 203 calculates that the communication time between the terminal 10-1 and the base station 20 is 1.338 seconds. Further, it is assumed that the transmission rate calculation unit 204 calculates the transmission rate at the current time as 30 bytes / RB based on the actual values of the transmission rates of the past three times. Further, it is assumed that the number of communication terminals is calculated by the number of terminals calculation unit 205.

Further, it is assumed that the communication end deadline is 3 seconds. Further, it is assumed that the communication time is 1.338 seconds. Further, it is assumed that the unit radio resource is 1 RB. Further, it is assumed that the number of radio resources per millisecond is 50 RB. In that case, it is assumed that the index calculation unit 206 calculates the number of surplus radio resources by using the above number 2. In that case, the index calculation unit 206 calculates that the remaining communication time is 1.662 seconds (= 3-1.338). Then, the index calculation unit 206 calculates that the number of radio resources _NR is 83100 (= 1.662 × 1000 × 50). Additionally, index calculation unit 206 uses the number 2 above, to calculate the surplus radio resources number N _S is 14000 (= (83100 × 30 / 3-411 × 1000) / 30).

Further, it is assumed that the index calculation unit 206 calculates the quality index value using the above equation 3. Here, it is assumed that the constant C in the above equations 3 and 4 is 30,000. In that case, a constant C> = surplus radio resources the number N _S. Therefore, the index calculation unit 206 calculates that the quality index value I ₁ corresponding to the terminal 10-1 is 1 by using the above equation 3. Further, the index calculation unit 206 calculates that the quality index difference corresponding to the terminal 10-1 is 1 by using the above equation 4.

When the index calculation unit 206 calculates the quality index difference corresponding to the terminal 10-1, the process returns to step S1202 and the process is continued. Specifically, the base station 20 calculates the quality index difference corresponding to the terminals 10-2 and the terminals 10-3.

When the index calculation unit 206 calculates the quality index difference corresponding to all the target terminals (for example, terminal 10-1, terminal 10-2, terminal 10-3) (that is, Yes branch in step S1202), The transition to step S1209.

In step 1209, the radio resource allocation unit 207 determines the terminal 10 to which the radio resource is allocated based on the quality index difference.

[Modification 1]
As a modification 1 of the base station 20 according to the present embodiment, the radio resource allocation unit 207 may prioritize the terminal 10 whose quality index difference increases in the next TTI as the target for allocating the radio resource. That is, the radio resource allocation unit 207 gives priority to the terminal 10 whose second-order differential value with respect to the number of radio resources of the quality index value increases as the target for allocating the radio resources when the radio resources are allocated next time (next TTI). May be good.

For example, it is assumed that the quality index differences corresponding to two or more terminals 10 are the same. In that case, by considering the second-order differential value of the quality index value with respect to the number of radio resources when allocating the radio resources next time, the radio resource allocation unit 207 will allocate the radio resources for each terminal 10 next time. Radio resources can be allocated to the terminal 10 so that the sum of the quality index values becomes large.

[Modification 2]
As a modification 2 of the base station 20 according to the present embodiment, the radio resource allocation unit 207 may determine the terminal 10 to which the radio resource is allocated in consideration of the quality index difference between the terminals 10. .. The radio resource allocation unit 207 contributes to increasing the number of terminals satisfying a predetermined communication quality while considering the fairness between the terminals 10 by considering the quality index difference between the terminals 10.

As described above, in the communication system 1 according to the present embodiment, the base station 20 decides to allocate the radio resource to the terminal 10 whose quality index difference satisfies a predetermined condition. By using the quality index difference, the base station 20 can prevent, for example, allocating wireless resources to the terminal 10 whose radio wave quality is extremely poor and which is unlikely to satisfy a predetermined communication quality. Further, the base station 20 can prevent the terminal 10 from allocating excessive radio resources beyond a predetermined communication quality by using the quality index difference. Therefore, the communication system 1 according to the present embodiment contributes to increasing the number of terminals satisfying a predetermined communication quality. Further, the communication system 1 according to the present embodiment contributes to improving the utilization efficiency of wireless resources.

[Second Embodiment]
The second embodiment will be described in more detail with reference to the drawings.

In this embodiment, the base station receives the residual communication amount and the communication time. In the description of the present embodiment, the description of the portion overlapping with the above-described embodiment will be omitted. Further, in the description of the present embodiment, the same components as those of the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted. Further, in the description of the present embodiment, the description of the same effects as those of the above-described embodiment will be omitted.

FIG. 10 is a diagram showing an example of the overall configuration of the communication system 1a according to the present embodiment. Referring to FIG. 10, the communication system 1a includes a terminal 10 (10-1, 10-2, 10-3), a base station 21, a server device 30, and a communication monitoring device 51. The difference between the communication system 1a shown in FIG. 10 and the communication system 1 shown in FIG. 2 is that the communication system 1a shown in FIG. 10 includes a communication monitoring device 51. Further, the communication system 1a shown in FIG. 10 includes a base station 21 instead of the base station 20 shown in FIG. Note that FIG. 10 shows three terminals 10, but this does not mean that the number of terminals is limited to three. The communication system 1a according to the present embodiment may be configured to include two or four or more terminals 10.

The base station 21 and the server device 30 are connected via the network 40. Further, the communication monitoring device 51 connects to the network 40 and monitors the communication between the server device 30 and the base station 21.

Specifically, the communication monitoring device 51 monitors the communication including the packet addressed to the terminal 10. Then, the communication monitoring device 51 monitors the communication including the packet addressed to the terminal 10 to calculate the residual communication amount and the communication time corresponding to each terminal 10. The communication monitoring device 51 may calculate the residual communication amount and the communication time by using the same method as that of the base station 20 according to the first embodiment.

For example, the communication monitoring device 51 may acquire the value of the Content-Length field from the HTTP header included in the packet addressed to the terminal 10. Then, the communication monitoring device 51 may calculate the residual communication amount corresponding to the terminal 10 based on the acquired value of the Content-Length field.

For example, the communication monitoring device 51 may determine the time when the residual communication amount of the terminal 10 changes from 0 to a value larger than 0 as the communication start time between the terminal 10 and the base station 21. Then, the communication monitoring device 51 may calculate the time elapsed from the communication start time from the base station 21 to the terminal 10 as the communication time.

The communication monitoring device 51 generates communication information in which the terminal identification information, the residual communication amount corresponding to the terminal identification information, and the communication time corresponding to the terminal identification information are at least associated with each other. Then, the communication monitoring device 51 notifies the base station 21 of the generated communication information.

As described above, the terminal identification information may be the MAC address, IP address, RNTI, or the like of the terminal 10. That is, the communication monitoring device 51 may generate communication information in which the MAC address of the terminal 10, the residual communication amount, and the communication time are at least associated with each other. Alternatively, the communication monitoring device 51 may generate communication information in which the IP address of the terminal 10, the residual communication amount, and the communication time are at least associated with each other. Alternatively, the communication monitoring device 51 may generate communication information in which the RNTI of the terminal 10 is at least associated with the residual communication amount and the communication time.

When the terminal identification information is information used for communication such as MAC address, IP address, RNTI, etc., the communication monitoring device 51, the base station 21, etc. allocate new information to the terminal 10 in order to identify the terminal 10. No need.

Further, the communication information may be configured to further include information that specifies the type of communication packet (moving image, still image, voice packet, etc.). In that case, the communication monitoring device 51 communicates by associating the terminal identification information, the residual communication amount corresponding to the terminal identification information, the communication time corresponding to the terminal identification information, and the information specifying the type of the communication packet. Information may be generated.

Alternatively, the communication information may be configured to further include information that identifies an application that operates at the terminal 10 that is the destination of the packet to be monitored. In that case, the communication monitoring device 51 may guess the application that operates at the terminal 10 of the destination of the packet to be monitored, based on the communication content to be monitored.

For example, the communication monitoring device 51 monitors HTTP communication. In that case, the communication monitoring device 51 specifies the domain of the URL (Uniform Resource Locator) in the HTTP communication to be monitored. Then, the communication monitoring device 51 may infer an application that operates at the terminal 10 of the destination of the packet to be monitored based on the specified domain. Then, the communication monitoring device 51 operates at the terminal 10 of the destination of the packet to be monitored, the value corresponding to the communication quality required by the application, the residual communication amount corresponding to the terminal 10, and the terminal 10 and the base station. Communication information may be generated in association with the communication time between 21. In the following description, the value according to the communication quality required by the application is referred to as an application estimated value.

For example, a calling application should operate with higher communication quality than an email application. Therefore, the communication monitoring device 51 may determine a value larger than the application estimated value corresponding to the e-mail application as the application estimated value corresponding to the call application.

Further, it is assumed that the communication between the terminal 10 and the server device 30 is encrypted communication, and it is difficult for the communication monitoring device 51 to obtain the residual communication amount corresponding to the terminal 10. In that case, the communication monitoring device 51 may calculate a predicted value (also referred to as a second predicted value) of the residual communication amount based on the probability distribution of the residual communication amount instead of the residual communication amount. For example, the communication monitoring device 51 may calculate the probability distribution of the residual communication amount based on the distribution of the past communication amount corresponding to the terminal 10. Then, the communication monitoring device 51 may calculate a predicted value (second predicted value) of the residual communication amount based on the probability distribution of the residual communication amount. Then, the communication monitoring device 51 associates the terminal identification information with the predicted value (second predicted value) of the residual communication amount corresponding to the terminal identification information and the communication time corresponding to the terminal identification information. Information may be generated. That is, the communication information may include a predicted value (second predicted value) of the residual communication amount.

FIG. 11 is a diagram showing an example of communication information. FIG. 11A shows an example of communication information in which the terminal identification information, the residual communication amount corresponding to the terminal identification information, and the communication time corresponding to the terminal identification information are associated with each other. For example, the first line (the title line is the 0th line) in FIG. 11A indicates that the residual communication amount corresponding to the terminal 10 of the terminal identification information “1” is 569,302 bytes. Further, the first line of FIG. 11A shows that the communication time between the terminal 10 of the terminal identification information “1” and the base station 21 is 1.435 seconds.

Further, as shown in FIG. 11B, the communication monitoring device 51 provides communication information in a data format in which the terminal identification information, the residual communication amount, and the communication time are separated by using ", (comma)". It may be generated. For example, the information shown in the first line of FIG. 11 (b) is the same as the information shown in the first line (the title line is the 0th line) of FIG. 11 (a). Note that FIG. 11 is an example of communication information, and is not intended to limit the format of communication information.

FIG. 12 is a block diagram showing an example of the internal configuration of the base station 21 according to the present embodiment. The base station 21 includes a packet transmission / reception unit 201, a transmission rate calculation unit 204, a terminal number calculation unit 205, an index calculation unit 216, a radio resource allocation unit 207, and a communication information reception unit 211. .. The same components as those of the base station 20 according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 13 is a block diagram showing an example of the hardware configuration of the base station 21 according to the present embodiment. Note that FIG. 13 is an example of the hardware configuration of the base station 21, and does not mean that the hardware configuration of the base station 21 is limited to the configuration shown in FIG.

The communication information receiving unit 211 receives the communication information corresponding to the terminal 10 from the communication monitoring device 51. Then, the communication information receiving unit 211 notifies the index calculation unit 216 of the received communication information. As shown in FIG. 13, the communication information receiving unit 211 may be realized by using the communication interface 2111, the processor 2112, and the memory 2113.

The index calculation unit 216 calculates the quality index value by using the communication information received by the communication information receiving unit 211. As shown in FIG. 13, the index calculation unit 216 may be realized by using the communication interface 2161, the processor 2162, and the memory 2163.

Specifically, the index calculation unit 216 calculates the quality index value based on the communication information, the transmission rate, and the number of communication terminals. Here, as described above, the transmission rate calculation unit 204 notifies the index calculation unit 216 of the calculated transmission rate. Further, the terminal number calculation unit 205 notifies the index calculation unit 216 of the calculated number of communication terminals.

Then, the index calculation unit 216 extracts the residual communication amount and the communication time corresponding to the terminal 10 for which the quality index value is calculated from the notified communication information. Then, the index calculation unit 216 calculates the quality index value of the target terminal 10 based on the residual communication amount extracted from the communication information, the communication time extracted from the communication information, the transmission rate, and the number of communication terminals. To do. Then, the radio resource allocation unit 207 determines the terminal 10 to which the radio resource is allocated based on the calculated change amount (quality index difference) of the quality index value.

Alternatively, the index calculation unit 216 calculates the expected value of the quality index value (also referred to as the second expected value) by using the predicted value (second predicted value) of the residual communication amount included in the communication information. You may. In that case, the radio resource allocation unit 207 determines the terminal 10 to which the radio resource is allocated based on the calculated change amount of the second expected value.

Next, the operation of the base station 21 according to the present embodiment will be described with reference to FIGS. 14 and 15.

FIG. 14 is a flowchart showing an example of an operation when the base station 21 receives communication information from the communication monitoring device 51.

In step S2001, the communication information receiving unit 211 waits for the reception of the communication information. Specifically, the communication information receiving unit 211 waits for the reception of the communication information transmitted from the communication monitoring device 51.

In step S2002, the communication information receiving unit 211 determines whether or not the communication information has been received. If the communication information is not received (No branch in step S2002), the process returns to step S2001 and the process is continued. On the other hand, when the communication information is received (Yes branch in step S2002), the communication information receiving unit 211 notifies the communication information to the index calculation unit 216 and stores the communication information (step S2003). Specifically, the communication information receiving unit 211 notifies the communication information to the index calculation unit 216, and stores the communication information in the memory 2113 of the communication information receiving unit 211. If the communication information is already stored in the memory 2113 of the communication information receiving unit 211, the communication information receiving unit 211 deletes the stored communication information and stores the stored communication information in the memory 2113 of the communication information receiving unit 211. The newly received communication information may be stored. Then, the process returns to step S2001 and the process is continued.

FIG. 15 is a flowchart showing an example of an operation when calculating the quality index difference corresponding to each terminal 10 and allocating wireless resources to the terminal 10. Since the operations from step S1201 to step S1203 are the same as the operations of the base station 20 according to the first embodiment, detailed description thereof will be omitted.

When the index calculation unit 216 selects the target terminal 10 for calculating the quality index value (step S1203), the process proceeds to step S2201. In the following description, a case where the index calculation unit 216 selects the terminal 10-1 will be described as an example.

In step S2201, the index calculation unit 216 extracts the residual communication amount and the communication time corresponding to the selected terminal 10-1 from the communication information. Then, the process proceeds to step S1206. Since the processes from step S1206 to step S1209 are the same as the operation of the base station 20 according to the first embodiment, detailed description thereof will be omitted.

When the communication information includes the application estimation value, the index calculation unit 216 may change the weight of the quality index value according to the application estimation value included in the communication information. _{Specifically, the index calculation unit 216 may multiply the quality index value I k} , which is calculated by using the above equation 3, by the application estimated value α, and _{calculate αI k} as the quality index value.

Here, it is assumed that the communication monitoring device 51 determines a value according to the communication quality required by the application as the application estimated value α. In particular, it is assumed that the communication monitoring device 51 determines the application estimated value α so that the higher the communication quality required by the application, the larger the application estimated value α. Additionally, index calculation unit 216, and calculates the .alpha. I _k of the as a quality index value. _{In that case, the index calculation unit 216 calculates the quality index value αI k} so that the higher the communication quality required by the application, the larger the quality index value.

When the communication information includes the predicted value of the residual communication amount, the index calculation unit 216 may calculate the quality index value by using the predicted value of the residual communication amount. Specifically, the index calculation unit 216 may calculate the expected value of the quality index value based on the predicted value of the residual communication amount included in the communication information. Then, the index calculation unit 216 may calculate the quality index difference based on the expected value of the quality index value.

The communication between the terminal 10 and the server device 30 is encrypted communication, and it may be difficult for the communication monitoring device 51 to obtain the residual communication amount corresponding to the terminal 10. However, the base station 21 contributes to allocating wireless resources to an appropriate terminal 10 by calculating the expected value of the quality index value by using the predicted value of the residual communication amount. As a result, the base station 21 contributes to increasing the number of terminals that satisfy a predetermined communication quality even when the communication between the terminal 10 and the server device 30 is encrypted communication.

As described above, in the communication system 1a according to the present embodiment, the base station 21 receives the communication information related to the communication of the terminal 10 from the communication monitoring device 51. Then, in the communication system 1a according to the present embodiment, the base station 21 calculates the quality index value corresponding to each terminal 10 based on the received communication information, and supplies wireless resources to the appropriate terminal 10. assign. Therefore, the communication system 1a according to the present embodiment contributes to increasing the number of terminals satisfying a predetermined communication quality and also contributes to reducing the load on the base station 21.

Further, the base station 21 may not have sufficient processing performance in order to calculate the residual communication amount and the like corresponding to the terminal 10. However, in the communication system 1a according to the present embodiment, the communication monitoring device 51 calculates the residual communication amount and the like corresponding to the terminal 10. Therefore, the communication system 1a according to the present embodiment has a predetermined communication even when the base station 21 does not have sufficient processing performance for calculating the residual communication amount and the like corresponding to the terminal 10. Contributes to increasing the number of terminals that meet quality.

Further, in the communication system 1a according to the present embodiment, the base station 21 may calculate a quality index value according to the communication quality required by the application operating on the terminal 10. Then, in the communication system 1a according to the present embodiment, the base station 21 allocates wireless resources to the terminal 10 according to the communication quality required by the application running on the terminal 10. Therefore, the communication system 1a according to the present embodiment contributes to increasing the number of terminals satisfying a predetermined communication quality while considering the difference in communication quality required for each application.

Some or all of the above embodiments may also be described as, but not limited to, the following embodiments.

(Form 1) This is the same as that of the base station according to the first viewpoint.

(Form 2) The base station according to Form 1, wherein the index calculation unit calculates the quality index value based on the residual communication amount, the communication time, the transmission rate, and the number of communication terminals.

(Form 3) The base station according to Form 2, further comprising a communication amount calculation unit that calculates the amount of packets that are scheduled to be transmitted to the terminal and have not been transmitted as the residual communication amount.

(Form 4) The residual communication amount calculation unit calculates a predicted value of the residual communication amount for each terminal, and the index calculation unit uses the predicted value to obtain an expected value of the quality index value. Calculated, and the radio resource allocation unit determines the terminal to which the radio resource is allocated based on the calculated change amount of the expected value, preferably the base station according to the third embodiment.

(Form 5) When the communication amount calculation unit cannot calculate the predicted value of the residual communication amount, the radio resource allocation unit allocates the radio resource to a terminal that cannot calculate the predicted value of the residual communication amount, preferably. The base station according to the fourth embodiment.

(Form 6) A communication information receiving unit that receives communication information corresponding to the terminal from a device different from the terminal is provided, and the index calculation unit uses the communication information received by the communication information receiving unit. The base station according to any one of embodiments 2 to 5, preferably the base station for calculating the quality index value.

(Form 7) The base station according to Form 6, wherein the communication information includes at least one of the residual communication amount, the communication start time, and a value according to the communication quality required by the application.

(Form 8) The communication information includes a second predicted value of the residual communication amount, and the index calculation unit uses the second predicted value to obtain a second expected value of the quality index value. Calculated, and the radio resource allocation unit determines the terminal to which the radio resource is allocated based on the calculated change amount of the second expected value, preferably the base station according to the sixth embodiment.

(Form 9) The terminal is further provided with a transmission rate calculation unit that calculates the amount of packets that can be transmitted per unit amount of wireless resources as the transmission rate, preferably in any one of forms 2 to 8. The listed base station.

(Form 10) The base station according to any one of Forms 2 to 9, further comprising a communication time calculation unit that calculates the time elapsed since the start of communication with the terminal as the communication time.

(Form 11) The base station according to any one of Forms 2 to 10, further comprising a terminal number calculation unit that calculates the number of the terminals communicating with the own base station as the number of communication terminals. ..

(Form 12) This is the same as the communication system according to the second viewpoint.

(Form 13) A communication monitoring device is further included, the base station relays communication between the terminal and the server device, and the communication monitoring device monitors communication between the base station and the server device. The base station further includes a communication information receiving unit that receives communication information corresponding to the terminal from the communication monitoring device by generating communication information regarding communication between the terminal and the server device, and the index. The communication system according to the twelfth aspect, wherein the calculation unit calculates the quality index value by using the communication information received by the communication information receiving unit.

(Form 14) The communication control method according to the third viewpoint is as described above.

(Form 15) The program is as described in the fourth viewpoint.

The forms shown in the above-mentioned forms 12, 14 and 15 can be developed into the forms shown in the forms 2 to 11 in the same manner as the forms shown in the first form.

The disclosure of the above-mentioned patent documents and non-patent documents shall be incorporated into this document by citation. Within the framework of the entire disclosure (including the scope of claims) of the present invention, the embodiments can be changed and adjusted based on the basic technical idea thereof. In addition, various combinations or selections (partial) of various disclosure elements (including each element of each claim, each element of each embodiment, each element of each drawing, etc.) within the framework of all disclosure of the present invention. (Including deletion) is possible. That is, it goes without saying that the present invention includes all disclosure including claims, and various modifications and modifications that can be made by those skilled in the art in accordance with the technical idea. In particular, with respect to the numerical range described in this document, it should be interpreted that any numerical value or small range included in the range is specifically described even if there is no other description. In the present invention, when an algorithm, software, or flowchart or an automated process step is shown, it is obvious that a computer is used, and it is also obvious that the computer is equipped with a processor and a memory or a storage device. Is. Therefore, even if the specification is lacking, it is understood that these elements are naturally described in the present application.

1, 1a Communication system 10, 10-1, 10-2, 10-3 Terminal 20, 21, 1000 Base station 30 Server device 40 Network 51 Communication monitoring device 201, 1001 Packet transmission / reception unit 202 Residual communication volume calculation unit 203 Communication time Calculation unit 204 Transmission rate calculation unit 205 Number of terminals calculation unit 206, 216, 1002 Index calculation unit 207, 1003 Radio resource allocation unit 211 Communication information reception unit 2011, 2021, 2031, 2041, 2051, 2061, 2071, 2111, 2161 Communication Interface 2012, 2022, 2032, 2042, 2052, 2062, 2072, 2112, 2162 Processor 2013, 2023, 2033, 2043, 2053, 2063, 2073, 2113, 2163 Memory

Claims (10)

A packet transmitter / receiver that wirelessly communicates with two or more terminals,
For each terminal, an index calculation unit that calculates a quality index value indicating the probability of satisfying a predetermined communication quality, and
A radio resource allocation unit that allocates radio resources to at least one terminal based on the amount of change in the quality index value corresponding to two or more terminals.
Base station with. The base station according to claim 1, wherein the index calculation unit calculates the quality index value based on the residual communication amount for each terminal, the communication time, the transmission rate, and the number of communication terminals. The base station according to claim 2, further comprising a residual communication amount calculation unit that calculates the amount of packets scheduled to be transmitted to the terminal as the residual communication amount. The residual communication amount calculation unit calculates the predicted value when the predicted value of the residual communication amount can be calculated for each terminal based on the distribution of the communication amount with the terminal.
The index calculation unit calculates the expected value of the quality index value by using the predicted value.
The base station according to claim 3, wherein the radio resource allocation unit determines the terminal to which the radio resource is allocated based on the calculated change amount of the expected value. The wireless resource allocation unit cannot calculate the predicted value when the residual communication amount calculation unit cannot calculate the predicted value of the residual communication amount for each terminal based on the distribution of the communication amount with the terminal. The base station according to claim 3 , wherein the radio resource is allocated to the device. A communication information receiving unit that receives the residual communication amount corresponding to the terminal from a monitoring device that monitors the communication of the terminal is provided.
The base station according to any one of claims 2 to 5, wherein the index calculation unit calculates the quality index value based on the residual communication amount received by the communication information receiving unit. The communication information receiving unit receives at least one of a value corresponding to the communication quality communication start time, application requests, the base station according to claim 6. The base station according to any one of claims 2 to 7, further comprising a transmission rate calculation unit that calculates the amount of packets that can be transmitted per unit amount of wireless resources to the terminal as the transmission rate. 2 or more terminal and the wireless communication line cormorants base station,
For each terminal, a quality index value indicating the probability of satisfying a predetermined communication quality is calculated.
A communication control method for allocating wireless resources to at least one terminal based on the amount of change in the quality index value corresponding to two or more terminals. Processing to perform wireless communication with two or more terminals,
For each terminal, a process of calculating a quality index value indicating a probability of satisfying a predetermined communication quality, and
A process of allocating wireless resources to at least one terminal based on the amount of change in the quality index value corresponding to two or more terminals.
Is a program that causes the computer that controls the base station to execute.

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