JP6790508B2 - Data flow control method, wireless base station equipment, server equipment, relay equipment, communication system, program - Google Patents

Description

The present invention relates to a data flow control method, a radio base station device, a server device, a relay device, a communication system, and a program.

A sequence number (SN: Sequence Number) is assigned to a packet transmitted by TCP (Transmission Control Protocol), and the receiving side controls the order of sending the received packet to the upper layer in the order of the sequence number (Non-Patent Document 1). ). TCP is a layer 4 (transport layer) protocol in the OSI (Open Systems Interconnection) basic reference model.

Further, in TCP, an acknowledgment (ACK: Acknowledgment) is performed to send back to the transmitting side that the transmitted packet has been correctly received by the receiving side. A packet for which an acknowledgment has not been obtained within a certain period of time after the packet is transmitted is retransmitted (Non-Patent Document 1). This waiting time until retransmission is called a "retransmission timeout" (RTO: Retransmission Time Out).

Further, in TCP, congestion control is performed to control the amount of data transmitted by the transmitting side per unit time according to the congestion status of the network (Non-Patent Document 2). Specifically, a packet in a window called a “congestion window” (CWND: Congestion Window) provided on the transmitting side is transmitted. The size of this congestion window (Congestion Window Size) basically increases when an acknowledgment of a transmitted packet is obtained and decreases when a retransmission timeout occurs.

In recent years, in order to cope with the increase in network traffic due to the spread of the Internet, the capacity of wired communication is increasing, such as communication by optical fiber.

In addition, due to the increase in rich contents and rich applications due to the increase in network capacity and the sophistication of terminal devices, congestion control methods have been actively proposed in order to increase the speed of each communication flow.

Further, with the spread of mobile terminals such as smartphones and tablets, the ratio of transmitting and / or receiving the above network traffic by wireless communication is also increasing. Therefore, it is also important to increase the speed of wireless communication. For example, in 3GPP (Third Generation Partnership Project), LTE (Long Term Evolution) and LTE Advanced are being standardized.

The protocols defined by LTE and LTE Advanced correspond to the protocols below layer 2 (data link layer) in the OSI basic reference model. Therefore, in a communication system including a wireless communication system such as LTE, as illustrated in FIG. 14, the wireless terminal 910 and the server device 930 use a protocol such as TCP that is layer 3 (network layer) or higher in the OSI basic reference model. Use to communicate. On the other hand, the wireless terminal 910 and the wireless base station 920 communicate with each other using a layer 2 or lower protocol (LTE or LTE Advanced). FIG. 14 is a diagram schematically showing a protocol stack of U-Plane (User-Plane) in a communication system using LTE. In the radio section between the radio terminal 910 and the radio base station 920, layer 1 is PHY (Physical Layer: physical layer), layer 2 is MAC (Media Access Control: media access control), RLC (Radio Link Protocol: wireless link control), It consists of PDCP (Packet Data Convergence Protocol: Packet Data Convergence Protocol). In the C-Plane (Control Plane), the RRC (Radio Resource Control) on the PDCP allocates channels in the radio section, and controls the call with the radio terminal 910 and the core network node (for example, MME (Mobile Management Management)). It is performed by the NAS (Non-Access Stratum) protocol with Entry) and SGSN (Serving GPRS (General Packet Radio Service) Support Node). GTP-U (GPRS Tunneling Protocol User panel) on UDP (User Datagram Protocol) on the core network side of the radio base station 920 is a tunnel protocol for transmitting user data. P-GW (PDN (Packet Data Network) -Gateway) that connects to a radio base station via the core network S-GW (Serving-Gateway) (not shown) and also connects to a packet data network (for example, the Internet). The L2 interface between the 960 and the server device 930 may be Ethernet®.

FIG. 15 is a diagram schematically illustrating a communication system using LTE. As schematically shown in FIG. 15, the radio base station 920 and the server device 930 are connected to each other via a communication line network 940 (for example, an Internet and LTE core network (EPC: Evolved Packet Core)), and are wireless terminals. The 910 and the radio base station 920 are connected via the radio interface 950.

As described above, in the communication system including LTE, the protocol and communication characteristics are different between the wireless terminal 910 and the wireless base station 920 (wireless section) and between the wireless base station 920 and the server device 930 (wired section). different.

Further, in general, the band fluctuation (fluctuation of communication speed) is larger in the wireless section than in the wired section. Therefore, for the purpose of absorbing the influence of the band fluctuation in the radio section, the radio base station 920 includes a buffer 921 for temporarily storing data addressed to the radio terminal 910. The buffer 921 of the radio base station 920 stores, for example, the data addressed to the radio terminal 910 arriving from the server device 930 until the transmission to the radio terminal 910 in layer 2 is completed.

However, the fluctuation range of the communication speed (throughput) in the radio section is very wide, for example, from several Kbps (Kilo bits per second) to several hundreds of Mbps (Mega bits per second).

Therefore, it is necessary to control the amount of data inflow from the server device 930 into the buffer 921 of the wireless base station 920 so as to match the amount of data transmitted from the buffer 921 to the wireless terminal 910. This is because if such control is not performed, overflow (data overflow) or underflow (data depletion) of the buffer 921 may occur.

For example, when the buffer 921 overflows due to congestion, the data that cannot fit in the buffer 921 is discarded together with the packet (packet loss). Then, when the packet is discarded, TCP retransmits the packet from the server device 930, which is the source of the packet. At the same time, TCP performs the above-mentioned congestion control. That is, when a packet is lost due to congestion or the like, congestion is avoided by reducing the congestion window, which is the upper limit of the amount of data that the transmitting side can transmit at one time. As a result, the congestion window is reduced, and the communication speed on the communication line 940 between the server device 930 and the radio base station 920 is reduced.

On the other hand, when an underflow occurs in the buffer 921 of the wireless base station 920, there is no data (packet) transmitted from the buffer 921 to the wireless terminal 910, and the wireless band of the wireless interface 950 between the wireless base station 920 and the wireless terminal 910 is used. The problem of reduced efficiency arises.

In order to solve the above problem, the amount of data stored in the buffer 921 of the radio base station 920 addressed to the radio terminal 910 approaches the amount of data transmitted for a predetermined time based on the communication speed of the radio section of the radio terminal 910. In addition, some techniques for controlling the amount of data flowing into the buffer 921 have been proposed.

For example, in Patent Document 1, the control station that relays data addressed to a mobile station and a base station that temporarily stores the data transmitted from the control station in a buffer and transmits the data to the mobile station. A method for controlling the amount of data inflow to a base station, wherein the data moves based on the transmission rate of the radio link between the base station and the mobile station and the amount of the data retained in the buffer. A step of determining the scheduled buffer retention time to be retained in the buffer before being transmitted to the station, and a step of controlling the transmission amount of the data transmitted from the control station based on the determined buffer retention scheduled time. A data inflow control method including the above is disclosed. According to the method disclosed in Patent Document 1, the base station monitors the transmission rate (communication speed of the radio section) of the radio link between the base station and the mobile station. Then, the base station uses the current transmission rate obtained by monitoring and the amount of data addressed to the mobile station retained in the buffer of the base station to determine the amount of data addressed to the mobile station retained in the buffer. The data inflow amount into the buffer required to obtain the transmission data amount for a predetermined time based on the transmission rate of the mobile station is calculated, and the information regarding the calculated data inflow amount is notified to the control station. The control station controls the amount of data transmitted from the control station to the mobile station based on the information regarding the amount of data inflow notified from the base station.

Further, Patent Document 2 discloses a technique relating to a mobile communication system including a radio base station and a base station control device (PCF: Packet Control Function). The wireless base station receives data rate information indicating an expected value of the downlink data rate estimated based on the reception state of the wireless communication terminal from the wireless communication terminal, and the average value of the data rate information in a certain period is preset. It is determined whether or not the data rate threshold is exceeded, and when it is determined that the average value does not exceed the data rate threshold, the average value is below the threshold indicating that the data rate threshold is not exceeded. The notification is transmitted to the base station control device. When the base station control device receives the sub-threshold notification, it determines and determines to reduce the communication band allocated to the communication executed between the wireless communication terminal and the communication destination device of the wireless communication terminal. The communication band is notified to the communication destination device.

In mobile communication, wireless resources such as frequency band and transmission power that can be used for communication are limited. Therefore, in order to realize high speed and large capacity, it is required to improve the efficiency of use of wireless resources.

In mobile communication, the management of wireless resources is generally performed by the scheduler of a wireless base station.

Generally, the scheduler of a wireless base station allocates wireless resources to each wireless terminal or each bearer based on the quality information of the wireless line that is periodically fed back from the wireless terminal. Here, the bearer refers to a logical line set between a wireless terminal and a wireless base station, between a wireless terminal and a mobile core network, between a wireless base station and a mobile core network, and the like. .. In LTE, wireless bearer (RB: Radio Bearer), network bearer (Evolved Packet System (EPS) Bearer, E-UTRAN (Evolved Universal Terrestrial Radio Access, Network) Base and so on. The EPS bearer is a bearer that transfers a user IP packet established between the PGW and the wireless terminal for each wireless terminal (UE: User Equipment). The E-RAB is a radio access bearer set between a radio base station (eNodeB) and a radio terminal (UE: User Equipment) in a radio access network (RAN: Radio Access Network). The S1 bearer is a bearer established between a radio base station (eNodeB) and an SGW. The S5 / S8 bearer is a bearer established between the SGW and the PGW.

According to the method disclosed in Non-Patent Document 3, the scheduler of the radio base station has an instantaneous rate expected when allocating radio resources calculated from the quality information of the radio line periodically fed back from the radio terminal. Radio resources are allocated based on the radio resource allocation index (also referred to as "radio resource allocation priority") calculated from the two, the average rate calculated from the transmission history of the radio terminal.

In the case of LTE, the scheduler of the radio base station is a resource block (RB: Resource Block), which is the minimum allocation unit of a frequency block that can be assigned to each radio terminal or each bearer, or a resource block group consisting of a plurality of RBs (RB). RBG: Resource Block Group) The allocation index is calculated for each.

As the instantaneous rate used for calculating the allocation index, CQI (Cannel Quality Indicator) included in CSI (Channel State information), which is the quality information of the wireless line fed back from the wireless terminal to the wireless base station, is used.

The radio base station is generally TBS (Transport Block Size) per RB or TBS per RBG that can be transmitted by MCS (Modulation and Coding Scheme) determined based on the radio line quality converted from CQI.

The average rate is a time average value of the number of transmission bits for each TTI (Transmission Time Interval), which is the minimum time unit for allocating radio resources. For example, the value obtained by dividing the instantaneous rate by the average rate is used as a radio resource allocation index (allocation priority).

Generally, the scheduler of a radio base station allocates RBs in order from the radio terminal or bearer having the largest allocation index. As a result, the allocation of each wireless terminal to the RB having a relatively high instantaneous wireless line quality is prioritized over the average wireless line quality. Therefore, it can contribute to the improvement of wireless capacity.

Also, the average rate will decrease if no radio resources are allocated. As the average rate decreases, the value obtained by dividing the instantaneous rate by the average rate (radio resource allocation index) increases, and the probability of allocation of radio resources at the next allocation opportunity increases. As a result, even wireless terminals with poor communication path quality have opportunities to allocate wireless resources. Therefore, it can contribute to the fairness of the allocation opportunity of wireless resources among wireless terminals.

In recent years, the breakdown of mobile data traffic has also diversified, so in addition to realizing high speed and large capacity, it is possible to stably provide each application with good quality of experience (QoE). It is one of the important themes in the competitive strategy of telecommunications carriers. Therefore, a scheduler that considers QoE is drawing attention.

According to the method disclosed in Patent Document 3, the radio base station identifies the traffic type of the packet arriving from the mobile core network, and sets the allowable delay amount and the target transmission rate according to the identified traffic type. Then, the radio base station controls the allocation of radio resources to each packet so as to satisfy the allowable delay amount and the target transmission rate. For example, if the transmission rate of a particular communication measured by a radio base station is less than the target transmission rate specified by the traffic type of the communication, the radio resource allocation priority for the communication is increased. ..

Further, according to the method disclosed in Patent Document 4, the radio base station manages a QoE function indicating the relationship between the allocation of radio resources and QoE for each traffic type. The scheduler of the wireless base station identifies the traffic type of each wireless terminal, provisionally allocates wireless resources to the wireless terminal by the method disclosed in Non-Patent Document 1, and performs a QoE function based on the provisional allocation result. It is used to calculate the QoE of each wireless terminal. Then, the scheduler of the wireless base station temporarily allocates a part of the wireless resources to the wireless terminal whose calculated QoE satisfies the required condition specified for each traffic type within the range where the wireless terminal satisfies the predetermined condition. The calculated QoE is accommodated to a wireless terminal that does not meet the requirements specified for each traffic type. As a result, it is possible to improve the QoE of the wireless terminal that does not satisfy the predetermined condition while satisfying the predetermined QoE for the wireless terminal that satisfies the required condition.

Japanese Patent No. 4176576 Japanese Unexamined Patent Publication No. 2008-141258 Japanese Patent No. 4335619 Japanese Patent No. 5011408

J. Postel, "Transmission Control Protocol", STD 7, RFC 793, Sept. 1981 M. Allman, V.I. Paxson, W. et al. Stevens, "TCP Congestion Control", RFC 2581, April 1999 Christian Wengeter et al, "Fairness and Throughput Analysis for Generalized Proportionally Fair Frequent Scheduling in OFDMA," VTC 2005-Sp. 2005 IEEE 61st (Volume: 3) Omori et al., "Effect of Frequency Scheduling Considering QoS-Based Delay in Downlink Spread OFDM Broadband Radio Access", Shingaku Giho RCS2004-276 (January 2005)

An analysis of related technologies is given below.

When the priority of allocating wireless resources to each wireless terminal is changed, the amount of wireless resources allocated to each wireless terminal increases or decreases, so that the throughput of the wireless section of each wireless terminal changes rapidly.

At this time, the technique disclosed in Patent Document 1 or Patent Document 2 has a problem that the scheduler of the radio base station does not sufficiently cope with a sudden change in the communication speed of the radio section. This point will be described with reference to FIGS. 16 and 17. 16 and 17 are views newly created by the inventor of the present application in order to explain the problems of the present invention.

For example, for a wireless terminal whose current wireless section throughput is low and transmission completion within the allowable delay is severe, the wireless resource allocation priority is updated (increased) by the scheduler of the wireless base station ((1) in FIG. 16 ) To (2)), when the allocation priority of a certain wireless terminal becomes relatively high, the throughput of the wireless section of the wireless terminal rapidly increases due to the increase in the allocated radio resources. Therefore, the amount of data transmitted from the buffer of the radio base station increases rapidly.

At this time, in the technique disclosed in Patent Document 1 or Patent Document 2, information relating to the amount of data flowing into the buffer of the radio base station based on the measured value or the average value of the throughput of the radio section used for control is provided to the radio base station. Since the data is fed back to the control station (control device), it takes time for the control station (control device) to perform control reflecting the rapid increase in throughput in the radio section. The amount of data flowing into the buffer of the radio base station does not increase until the control reflecting the rapid increase in throughput of the radio section is started.

Therefore, in the technique disclosed in Patent Document 1 or Patent Document 2, the amount of data flowing into the buffer of the radio base station (data inflow amount) is the amount of data transmitted from the buffer of the radio base station (data transmission). There will be a time period during which the amount of data to the wireless terminal stored in the buffer will decrease. That is, as shown in FIG. 16 (2), as a result of increasing the allocation priority, the amount of data stored in the buffer of the radio base station becomes smaller than the target size. If the state of (2) in FIG. 16 continues for a long time, buffer underflow (data depletion) occurs as shown in (3) of FIG. When buffer underflow (data depletion) occurs, the amount of data required to complete transmission within the permissible delay cannot be transmitted to the wireless terminal, and the QoE of the wireless terminal cannot be improved.

Further, if the radio resource allocated to the wireless terminal whose transmission completion within the allowable delay is severe is increased, the throughput of the wireless section of the other wireless terminal is reduced due to the decrease in the wireless resource allocated to the other wireless terminal. It will decrease sharply. Therefore, in the other wireless terminal, the amount of data transmitted from the buffer may decrease sharply. In this case, in the technique disclosed in Patent Document 1 or Patent Document 2, it takes time for the control station (control device) to perform control reflecting the rapid decrease in throughput in the radio section. Therefore, the amount of data flowing into the buffer of the radio base station (data inflow amount) becomes larger than the amount of data sent from the buffer (data sending amount), and the other wireless terminal is stored in the buffer. There will be a time zone when the amount of data addressed to the destination increases ((2) in FIG. 17). If this time zone is long, a buffer overflow (data overflow in FIG. 17 (3)) occurs. When a buffer overflow (data overflow) occurs, the data (packet) that cannot fit in the buffer and is discarded (packet loss) is retransmitted by TCP, and the communication speed is reduced by congestion control. As a result, the QoE of the wireless terminal is lowered.

The above-mentioned problem is not limited to the case where the priority of allocating wireless resources to each wireless terminal is changed by a scheduler or the like.

For example, considering the state of the application and the quality of the wireless line
-Transmission power allocated to the reference signal (RS: Reference Signal),
And downlink data channel (PDSCH: Physical Downlink Shared Channel) parameters relating to the transmission power to be allocated to _{(RS-to-PDSCH Offset,} P A, P B, ρ B / ρ A, δ power-offset),
-Transmission mode (Transmission Mode),
-Actually used antenna configuration (Antenna Configuration),
-Transmission beam formed by beam forming,
-Carrier frequency used for wireless communication (Carrier Frequency) or-Parameters related to carrier frequency (E-UTRA (Evolved-Universal Terrestrial Radio Access) Operating Band, EARFCN (EUTRA Cable Frequency) Carrier Frequency) Wireless line quality and traffic load related to
-Component carrier used in carrier aggregation,
-Wireless terminal categories (UE (User Equipment) Category, DL (Down Link) Category, UL (Uplink) Category), RAT (Radio Access Technology), etc.
The same occurs when the radio parameters related to the allocation of radio resources are changed.

It is desired to realize a system that optimizes the amount of data flowing into the buffer of the radio base station and avoids overflow or underflow of the buffer even when the radio parameters related to the allocation of radio resources are changed (the present invention). Knowledge by the person).

The present invention has been made to solve such a problem, and one of the purposes thereof is to change the radio parameters related to the allocation of radio resources even when the radio base station changes the radio parameters of the radio base station. It is an object of the present invention to provide a data flow control method, a device, a communication system, and a program capable of avoiding overflow or underflow to a buffer.

According to the first aspect of the present invention, when there is a change in the radio parameter related to the allocation of radio resources, the radio base station that receives the data addressed to the radio terminal temporarily stores the data. The transmission amount estimation step of calculating the estimated value of the data transmission amount for the above in consideration of the change of the radio parameter, and
A data flow control method including an inflow amount control step for controlling an inflow amount of data into the buffer based on an estimated value of the data transmission amount from the buffer and the data accumulation amount stored in the buffer. Provided.

According to the second aspect of the present invention, a buffer for temporarily storing data sent from a source to a wireless terminal and data stored in the buffer to the wireless terminal based on the result of allocation of wireless resources. If there is a change in the function to transmit and the predetermined radio parameters related to the allocation of the radio resources, the estimated value of the amount of data transmitted from the buffer to the radio terminal is calculated in consideration of the change in the radio parameters. The amount of data inflow from the source to the buffer to the wireless terminal is calculated based on the transmission amount estimation unit, the estimated value of the data transmission amount, and the data storage amount stored in the buffer. A radio base station apparatus including an inflow amount control unit and an information notification unit that notifies the data inflow amount to the transmission source is provided.

According to the third embodiment of the present invention, the wireless base station has a function of receiving data inflow information to a wireless terminal calculated by the wireless base station via a communication network, and based on the data inflow information. Provided is a server device including an inflow amount control unit that controls the amount of data to be transmitted to the wireless terminal.

According to the fourth aspect of the present invention, there is a function of relaying data addressed to a wireless terminal connected between a wireless base station and a server device and transmitted from the server device to the wireless base station.
Data addressed to the wireless terminal that receives the data inflow information calculated by the wireless base station to the wireless terminal via the communication network and transmits the data to the wireless base station based on the data inflow information. A relay device including a data amount control unit for controlling the amount is provided.

According to the fifth aspect of the present invention, a communication system including a wireless terminal, a wireless base station, and a server device is provided.
The radio base station has a buffer for temporarily storing data sent from the server device to the radio terminal, and a function of transmitting the data stored in the buffer to the radio terminal based on the result of allocation of radio resources. , When there is a change in the predetermined radio parameter related to the allocation of the radio resource, the transmission amount estimation is calculated to calculate the estimated value of the data transmission amount from the buffer to the radio terminal in consideration of the change of the radio parameter. The inflow amount control unit that calculates the amount of data inflow from the server device to the buffer to the wireless terminal based on the unit, the estimated value of the data transmission amount, and the data storage amount stored in the buffer. And an information notification unit that notifies the server device of the data inflow amount.
The server device includes an inflow amount control unit that receives a data inflow amount transmitted from the radio base station and controls the amount of data sent to the radio base station to the radio terminal based on the data inflow amount information. ..

According to a sixth aspect of the present invention, there is provided a communication system including a wireless terminal, a wireless base station, a server device, and a relay device connected between the wireless base station and the server device. Will be done.
The radio base station temporarily stores data destined for the radio terminal transmitted from the server device via the relay device, and the radio terminal stores the data stored in the buffer based on the result of allocation of radio resources. If there is a change in the function to send to the address and the predetermined radio parameters related to the allocation of the radio resources, the estimated value of the amount of data transmitted from the buffer to the radio terminal in consideration of the change in the radio parameters. Based on the transmission amount estimation unit that calculates the data transmission amount, the estimated value of the data transmission amount, and the data storage amount stored in the buffer, the data inflow amount from the transmission source to the wireless terminal to the buffer is calculated. It includes an inflow amount control unit for calculating and an information notification unit for notifying the relay device of the data inflow amount.
The relay device relays the reception function of receiving the data inflow amount information to the wireless terminal calculated by the wireless base station and the data to the wireless terminal transmitted from the server device to the wireless base station. A data amount control unit that controls the amount of data transmitted to the radio terminal to be transmitted to the radio base station based on the data inflow amount information is included.

According to the seventh aspect of the present invention, a buffer for temporarily storing data addressed to a wireless terminal transmitted from a source is provided, and the data stored in the buffer is addressed to the wireless terminal based on the result of allocation of wireless resources. To the computer that configures the base station device including the function to send to
When there is a change in a predetermined radio parameter related to the allocation of the radio resource, a process of calculating an estimated value of the amount of data transmitted from the buffer to the radio terminal in consideration of the change of the radio parameter, and
A process of calculating the amount of data inflow from the source to the buffer to the wireless terminal based on the estimated value of the data transmission amount and the amount of data stored in the buffer.
The process of notifying the source of the data inflow amount and
A program is provided to execute.

According to the eighth aspect of the present invention, the computer constituting the server device is
Processing to receive data inflow information to wireless terminals calculated by a wireless base station via a communication network,
A process of controlling the amount of data transmitted to the wireless terminal to the wireless base station based on the data inflow amount information, and
A program is provided to execute.

According to the ninth aspect of the present invention, a relay device is configured which is connected between the wireless base station and the server device and relays data addressed to the wireless terminal transmitted from the server device to the wireless base station. To the computer
Processing to receive data inflow information to wireless terminals calculated by a wireless base station via a communication network,
A program for executing a process of controlling the amount of data transmitted to the wireless terminal to the wireless terminal based on the data inflow amount information is provided.

According to the present invention, a computer-readable recording medium (for example, HDD (Hard Disk Drive) or CD (Compact Disc), DVD (Digital Versaille Disc), semiconductor storage device, etc., which stores the seventh to ninth programs, respectively, etc. Non-transition computer readable recording medium) is provided.

According to the present invention, it is possible to avoid buffer overflow and underflow even when the radio base station changes the radio parameters related to the allocation of radio resources.

It is a figure which illustrates an example of the structure of the communication system in 1st Embodiment of this invention. It is a figure which schematically exemplifies an example of the function of the radio base station and the server device in the 1st Embodiment of this invention. It is a flow chart explaining an example of the operation procedure of the change detection part and the transmission amount estimation part of a radio base station in 1st Embodiment of this invention. It is a flow chart explaining an example of the operation procedure of the transmission amount estimation part of the radio base station in 1st Embodiment of this invention. It is a flow chart explaining an example of the operation procedure of the inflow amount control part of the radio base station in 1st Embodiment and 2nd Embodiment of this invention. (A) and (B) are flow diagrams for explaining the processing procedure of the inflow amount control unit of the server device in the first embodiment and the second embodiment of the present invention. It is a flow chart explaining an example of the operation procedure of the transmission amount estimation part of the radio base station in the 2nd Embodiment of this invention. It is a figure which schematically exemplifies an example of the structure of the communication system in the 3rd Embodiment of this invention. It is a figure which illustrates an example of the function of the radio base station and the server apparatus in the 3rd Embodiment of this invention. It is a flow chart explaining an example of the operation procedure of the transmission amount estimation part of the radio base station in the 3rd Embodiment of this invention. It is a flow chart explaining an example of the operation procedure of the transmission amount estimation part of the radio base station in 4th Embodiment of this invention. It is a figure which illustrates the structural example of the modification of the communication system in 5th Embodiment of this invention. (A), (B), and (C) are diagrams illustrating configuration examples (implementation examples in an information processing device) of a radio base station and a server device transmission control device according to an embodiment of the present invention. It is a figure which shows the protocol stack of the communication system using LTE. It is a figure which shows the communication system using LTE. It is a figure created for demonstrating the subject of this invention. It is a figure created for demonstrating the subject of this invention.

Next, an embodiment of the present invention will be described in detail with reference to the drawings. Reference numerals on the drawings referred to in the description of the embodiments of the present invention including the present embodiment are added to each element for convenience as an example to assist understanding, and any description of this outline is given. It is not intended to be limited.

<First Embodiment>
[Description of configuration / function]
FIG. 1 is a diagram schematically illustrating an example of a configuration of a communication system 1 according to an exemplary first embodiment of the present invention. Referring to FIG. 1, the communication system 1 includes a wireless terminal 10, a wireless base station 20, and a server device 30. Note that, for convenience of explanation, in FIG. 1, the communication system 1 is exemplified as a configuration including a wireless terminal 10, a wireless base station, 20 server devices, and 30 respectively. The number of wireless terminals 10 may be any number. Similarly, the number of radio base stations 20 and the number of server devices 30 may be any number. The wireless terminal 10 and the wireless base station 20 are configured to communicate with each other via the mobile access network 11.

Further, the radio base station 20 and the server device 30 are configured to communicate with each other via a communication line network 50 (NW: Network).

The communication line network 50 includes at least a mobile core network 51 and an external network 52 such as the Internet. The mobile core network 51 is connected to the external network 52 via a gateway (not shown). In this specification, the mobile core network 51 and the external network 52 are also collectively referred to as a communication line network 50.

Although not particularly limited, in the first embodiment of the present invention, the mobile access network 11 and the mobile core network 51 are each a mobile access network (EUTRAN: Evolved UMTS Terrestrial) in an LTE radio system (RAT: Radio Access Technology). Radio Access Network) and a mobile core network (EPC: Evolved Packet Core) are assumed. However, mobile access networks and mobile core networks in other wireless systems other than LTE such as UTRAN, UMTS (Universal Mobile Telecommunications System), and GSM (Global System for Mobile communications) may be assumed. Alternatively, the mobile access network 11 and the mobile core network 51 may be separate wireless systems. For example, the mobile core network 51 is an EPC in an LTE wireless system, and the mobile access network 11 is a Wi-Fi (Wi-Fi Alliance: registered trademark of Wi-Fi Alliance), a wireless LAN (Local Area Network), or a WiMAX (Worldwide Internet). It may be a wireless system other than LTE, such as Access), LoRaWAN (Long Range Wide Area Network: a registered trademark of LoRa Alliance), and MultiFire. The same applies to other embodiments described later.

The wireless terminal 10 is any one of a mobile phone terminal, a personal computer, a PHS (Personal Handyphone System) terminal, a PDA (Personal Data Assistant, Personal Digital Assistant), a smartphone, a tablet terminal, a car navigation terminal, a game terminal, and the like. is there. The wireless terminal 10 includes a CPU (Central Processing Unit), a storage device (memory), a transceiver (transmitter and receiver), an input device (key button and microphone), and an output device (display and speaker).

The wireless terminal 10 may be configured to realize the functions provided by the wireless terminal 10 by executing a program stored in a storage device (not shown) by a CPU (not shown). Although not particularly limited, the functions included in the wireless terminal 10 include, for example, the following functions.
-A function of communicating with the server device 30 via the wireless base station 20.
-A function to execute various communication services provided by the server device 30.
-A function of transmitting and / or receiving a wireless signal between a wireless base station 20 (a communication link (RRC (Radio Resource Control) Connection) is established) connected to the wireless terminal 10.
-CQI (Cannel Quality Indicator), RSRP (Reference Signal Received Power), and RSRQ (Reference Signal Received), which are reception quality indexes of the reference signal transmitted by the radio base station 20 based on the measurement setting information received from the radio base station 20. ), Etc. and report to the connected radio base station 20 (Measurement report: Quality Report).

Since each of the above functions included in the wireless terminal 10 is well known to those skilled in the art, the description of each component of the wireless terminal 10 will be omitted.

The radio base station 20 includes, for example, an information processing device (transmitter and receiver) (not shown). The information processing device includes a central processing unit (CPU: Central Processing Unit) and a storage device (memory and hard disk drive device (HDD: Hard Disk Drive)) (not shown). The radio base station 20 may be configured to realize the functions described later by the CPU executing the program stored in the storage device.

The server device 30 is a device that provides various communication services to the wireless terminal 10. Although not particularly limited, the server device 30 is, for example,
・ WWW (World Wide Web) server,
-FTP (File Transfer Protocol) server,
・ Mail server,
·file server,
・ Database server,
・ Application server,
・ Streaming server,
-DNS (Domain Name System) server,
・ Proxy server,
-It may be an edge server or the like.

The server device 30 includes an information processing device (not shown) and a communication interface. The information processing device includes a central processing unit (CPU) (not shown) and a storage device (memory and hard disk drive device (HDD: Hard Disk Drive)). The server device 30 may be configured to realize a function of providing various communication services to the wireless terminal 10 by the CPU executing a program stored in a storage device (not shown).

FIG. 2 is a diagram schematically illustrating an example of the functions of the radio base station 20 and the server device 30 of the communication system 1 of FIG.

Referring to FIG. 2, the radio base station 20 includes a basic function unit 201, a buffer 202, a communication control unit 203, a change detection unit 204, a transmission amount estimation unit 205, an inflow amount control unit 206, and information notification. The unit 207 is provided. As described above, in the operation of each functional unit described below, the central processing unit (CPU), transceiver (transmitter and receiver), and storage device (memory and HDD) of the radio base station 20 operate in cooperation with each other. Is realized by.

In FIG. 2, the basic functional unit 201 of the wireless base station 20 has a function provided by the wireless base station in a general wireless communication system. Although not particularly limited, the basic function unit 201 includes, for example, the following functions.
A function of transmitting and / or receiving a wireless signal between a wireless base station 20 and a wireless terminal 10 (with a communication link established) connected to the wireless base station 20.
A function of generating a reference signal used by the wireless terminal 10 to measure the communication path quality with the wireless base station 20.
-A function of accumulating transmission data addressed to each wireless terminal 10 arriving via the communication line network 50.
-A function to acquire and manage QCI (Quality of Service (QCI) Class Identifier) related to transmission data.
-A function to hold CQI, RSRP, and RSRQ reported from the wireless terminal 10.
-A function for managing the history of the wireless section throughput of the wireless terminal 10.
-Radio base station 20 such as the physical resource block (PRB: Physical Measurement Block) usage rate and the number of wireless terminals 10 connected to the wireless base station 20 (also referred to as "active UE number" (active wireless terminal number)). Ability to measure and manage measurable information. One physical resource block is formed by 180 KHz (KiloHerz) (12 subcarriers at 15 KHz intervals) on the frequency axis and time / frequency resources having a size of 1 ms on the time axis.

Since each of the above-mentioned functions included in the basic function unit 201 in the radio base station 20 is well known to those skilled in the art, further description thereof will be omitted in the present specification.

In FIG. 2, the buffer 202 of the wireless base station 20 has a function of temporarily accumulating and managing transmission data addressed to each wireless terminal 10 arriving from the server device 30 side via the communication line network 50.

The communication control unit 203 of the radio base station 20 has a function of managing radio resources included in the radio base station in a general wireless communication system. Although not particularly limited, the communication control unit 203 includes, for example, the following functions.
-RRC (Radio Resource Control) function that controls the wireless connection status between the wireless base station 20 and the wireless terminal 10.
-A function of determining the transmission mode (Transmission Mode) of each wireless terminal 10.
A function for determining the transmission power allocated to the physical downlink shared data channel (PDSCH: Physical Downlink Shared Channel) (shared data channel for transmitting downlink user data) of each wireless terminal 10.
-A function to determine the antenna configuration of each wireless terminal 10.
-A function of determining a carrier frequency used for communication of each wireless terminal 10.
-A function for determining whether or not carrier aggregation of each wireless terminal 10 can be applied.
A function of determining a component carrier used for communication of each wireless terminal 10.
-A function to calculate the allocation index of each wireless terminal 10.
-A function of determining a frequency block to be assigned to each wireless terminal 10 based on the calculated allocation index.

Since each of the above-mentioned functions of the communication control unit 203 is well known to those skilled in the art, further description thereof will be omitted.

In the present embodiment, the radio resource allocation index M (i, k) is calculated based on, for example, the following mathematical formula (1). For the mathematical formula (1), for example, the description of Non-Patent Document 4 and the like is referred to.

In formula (1)
・ I is the identification number of the wireless terminal 10,
-K represents the identification number of the resource block.

In the equation (1), the packet transmission delay can be considered in the first term on the right side. Further, in the second term, whether or not to resend can be considered. Further, in the third term, the desired signal-to-interference signal ratio SINR (Signal-to-Interference plus Noise power Ratio) can be considered.

・・・（１）

... (1)

In the above formula (1)
The first term α _Delay · M _Delay (i) on the right side is an allocation index that allows consideration of packet transmission delay. M _Delay (i) is given by, for example, the following mathematical formula (2). The M _Delay (i) is controlled based on the elapsed time since the packet was sent from the sender.

・・・（２）

... (2)

In the above formula (2)
_Treq (i) is the allowable delay of the packet,
t (i) is the elapsed time since the packet was sent from the source.
T _thresh (i) is an arbitrary threshold,
Represent each.

In the present embodiment, the allowable delay of the packet _Treq (i) is an allowable delay determined from the QCI regarding the transmission data addressed to the wireless terminal 10 acquired and managed by the basic function unit 201.

In general, in order to stably provide an application with good quality of experience (QoE), it is required to complete transmission of the packet within the allowable delay of the packet.

Therefore, for the packet sent from the source, the remaining time until the allowable delay of the packet, that is, the time obtained by subtracting the elapsed time t (i) of the packet from the allowable delay _Treq (i) of the packet: _Treq ( i) -t (i) if the threshold value _{T thresh} (i) _hereinafter, increasing the value of _{M Delay} (i) as a (> 0). _{Incidentally,} if the value of T req (i) -t (i ) is greater than the threshold value _{T thresh (i),} the value of _{M Delay} (i) is set to 0.

In the above equation (1), alpha _Delay of the first term of the right side α _Delay · _{M Delay} (i) _is a weighting coefficient _{M Delay} (i).

Next, in the above mathematical formula (1), the second term α _Type · M _Type (i) on the right side is an allocation index that can consider whether or not to retransmit. M _Type (i) is given by, for example, the following mathematical formula (3).

・・・（３）

... (3)

In the above formula (3), N _retrans (i) represents the number of retransmissions. If it is a retransmission packet (when the number of retransmissions N _retrans (i) is 1 or more), M _Type (i) is 1, and if it is not a retransmission packet (when the number of retransmissions N _retrans (i) is 0), M _Type (i). ) Is 0.

In the above equation (1), alpha _Type of the second term α _Type · _{M type} (i) _is the weighting factor of the _{M type} (i).

In this embodiment, the third term α _SINR · _{M SINR} of the equation (1) (i, k) of _M SINR (i, k), for example given by the following equation (4).

・・・（４）

... (4)

In the above formula (4)
The CQI _inst (i, k) represents the instantaneous CQI (most recent CQI) of the resource block (RB) of the identification number k reported from the wireless terminal 10 of the identification number i.
SINR (.) Represents a function that converts CQI to SINR.
SINR _ave (i, k) represents the average value of SINR for a predetermined period calculated by SINR (.).
SINR _thresh is any threshold.

SINR (・) outputs SINR (CQI _inst (i, k)) from the instantaneous CQI _inst (i, k) for each resource block based on the CQI-SINR conversion table in which CQI and SINR are associated with each other. It may be.

In the above equation (1), alpha _SINR of the third term _{α SINR · M SINR (i,} k) _is a weighting coefficient _M SINR (i, k).

The above formula (2) corresponds to the formula (2) of Non-Patent Document 4, the formulas (5) and (8) of Patent Document 3, and the above formula (4) is the formula (4) of Non-Patent Document 4. ), Corresponds to the mathematical formula (4) of Patent Document 3.

In the above equation Equation (4), when the threshold _{SINR thresh} is set to a large value, the average _{value: SINR} ave (i, k) instantaneous _SINR for _(CQI inst (i, k)) when the ratio is _{larger, M SINR} (I, k) increases and the average value: SINR _ave (i, k) is low (the reception state is poor) Even in the communication of the wireless terminal 10, the SINR (CQI _inst (i, k)) is relatively high. When good, M _SINR (i, k) increases. On the other hand, setting the threshold _{SINR thresh} small value _{(SINR ave (i, k)} > SINR thresh), the instantaneous _{SINR (CQI inst (i, k} )) _{higher, M} increase in SINR (i, k) Increases, and the more the communication with the wireless terminal 10 having a good reception state on average, the more opportunities for allocating wireless resources.

In FIG. 2, the change detection unit 204 of the radio base station 20 has a function of detecting changes in radio parameters related to the allocation of radio resources. Although not particularly limited, in the present embodiment, the radio parameter related to the allocation of the radio resource for detecting the change by the change detection unit 204 is the M _Delay (i) of the above formula (2).

In the above mathematical formula (2), the elapsed time t (i) from the transmission of the packet addressed to the wireless terminal 10 with the identification number i from the source is obtained by using, for example, the method disclosed in Patent Document 3 or the like. It may be a thing. In this case, the change detection unit 204 acquires the elapsed time t (i) in cooperation with the basic function unit 201 having a function of accumulating packets addressed to the wireless terminal 10 arriving via the communication line network 50. The change in the value of M _Delay (i) in the above formula (2) may be detected. Regarding the wireless parameters M _Type (i) and M _SINR (i, k), the change detection unit 204 is also based on the presence or absence of packet retransmission and the received SINR information on the wireless terminal 10 acquired by the basic function unit 201. Changes in each radio parameter may be detected.

The transmission amount estimation unit 205 of the radio base station 20 transmits the radio terminal 10 from the buffer 202 from the time when the change detection unit 204 detects the change of the radio parameter related to the allocation of the radio resource to the lapse of a predetermined time. It has a function to estimate the amount of data to be sent (referred to as "data transmission amount").

The amount of data transmitted from the buffer 202 estimated by the transmission amount estimation unit 205 of the radio base station 20 to the wireless terminal 10 is used by the inflow amount control unit 206.

The inflow amount control unit 206 of the radio base station 20 has the data transmission amount estimated by the transmission amount estimation unit 205 to the radio terminal 10 and the amount of data to be accumulated and managed by the buffer 202 (“data storage amount”). It has a function of calculating the amount of data (referred to as "data inflow amount") destined for the wireless terminal 10 to flow from the server device 30 side into the buffer 202. The amount of data inflow to the wireless terminal 10 into the buffer 202 calculated by the inflow amount control unit 206 is used by the information notification unit 207.

The information notification unit 207 of the radio base station 20 has a function of notifying the server device 30 of the information related to the data inflow amount to the wireless terminal 10 calculated by the inflow amount control unit 206.

In the present embodiment, the information notification unit 207 of the radio base station 20 has a function of manipulating the header area and the payload area of the packet of layer 3 or higher in the OSI basic reference model.

The information notification unit 207 of the wireless base station 20 notifies the server device 30 of the information related to the amount of data inflow of the wireless terminal 10 by using an IP (Internet Protocol) corresponding to the data sent by the wireless terminal 10 to the server device 30. ) This is done by concatenating (concatenating, concatenating) the information in the packet. However, this may be done by adding the information to the header area of the IP packet. In this case, the information may be added to, for example, an unused field in the IP header.

Further, the TCP (Transmission Control Protocol) used in the upper layer of the IP may be used by concatenating the information with the TCP segment (referred to as “TCP packet”) corresponding to the IP packet. .. Further, the information may be added to the header area (TCP header: minimum 20 bytes) of the TCP packet. In this case, the information may be added to an unused field or the like in the TCP header.

Alternatively, instead of TCP, UDP (User Datagram Protocol) is used to concatenate the information to the UDP datagram (referred to as "UDP packet") corresponding to the IP packet to perform the above notification. May be good. Further, the above notification may be performed by adding the information to the header area (UDP header: 8 bytes) of the UDP packet.

Alternatively, a new interface for notifying the information may be installed between the server device 30 and the wireless base station 20, and the information may be notified via the interface.

In FIG. 2, the server device 30 is composed of a basic function unit 301 and an inflow amount control unit 302. As described above, the operation of each functional unit described below is realized by the information processing device, the communication interface, and the storage device (memory, HDD, etc.) included in the server device 30 operating in cooperation with each other.

The basic function unit 301 of the server device 30 has a function of providing various communication services to the wireless terminal 10 as described above, and transmits signals to the wireless base station 20 and the wireless terminal 10 via a communication line network. / Or has a function to receive. As the function provided by the basic function unit 301, a function well known to those skilled in the art can be used. The description of each function provided in the basic function unit 301 will be omitted.

The inflow amount control unit 302 of the server device 30 is addressed to the wireless terminal 10 that is transmitted to the wireless base station 20 via the communication line network 50 based on the information related to the data inflow amount of the wireless terminal 10 notified from the wireless base station 20. It has a function to control the amount of data of.

In the present embodiment, the inflow amount control unit 302 of the server device 30 corresponds to, for example, an IP packet (data addressed to the server device 30 transmitted by the wireless terminal 10) arriving from the wireless base station 20 via the communication line network 50. ), The information regarding the amount of data inflow to the wireless terminal 10 into the buffer 202 of the wireless base station 20 may be acquired.

The same applies to the case where a TCP packet or a UDP packet is used instead of the IP packet in the notification to the server device 30 of the amount of data inflow to the wireless terminal 10 into the buffer 202 of the wireless base station 20. is there. That is, the inflow amount control unit 302 of the server device 30 corresponds to the TCP packet or the UDP packet (data addressed to the server device 30 transmitted by the wireless terminal 10) arriving from the radio base station 20 via the communication line network 50. ), The information regarding the data inflow amount of the wireless terminal 10 may be acquired.

Further, when a new interface for notifying the information is installed between the radio base station 20 and the server device 30, the result is as follows.

The radio base station 20 notifies the server device 30 of information regarding the amount of data flowing into the buffer 202 of the radio base station 20 to the radio terminal 10 via the new interface.

The inflow amount control unit 302 of the server device 30 has a function of acquiring information via the interface. The server device 30 acquires information relating to the amount of data inflow to the wireless terminal 10 into the buffer 202, which is notified via the interface.

[Explanation of operation]
Next, an operation procedure for optimizing the amount of data flowing into the buffer 202 of the radio base station 20 when the radio base station 20 changes the radio parameters related to the allocation of radio resources will be described.

FIG. 3 is a flow chart illustrating an example of an operation procedure of the change detection unit 204 and the transmission amount estimation unit 205 of the radio base station 20 described with reference to FIG. Referring to FIG. 3, the change detection unit 204 of the radio base station 20 detects a change in the radio parameter related to the allocation of radio resources (step S100).

When the change detection unit 204 detects a change in the radio parameter, the transmission amount estimation unit 205 transmits data from the buffer to, for example, all the radio terminals 10 that have established a radio link with the radio base station 20. The quantity estimation process (step S101) is executed. In FIG. 3, for the sake of simplicity of explanation, the amount of data transmitted to all the wireless terminals 10 (N units, N is an integer of 1 or more) that has established a wireless link with the wireless base station 20. Although the estimation process (step S101) is represented by a flowchart that is repeatedly executed as a subroutine, it goes without saying that the process of the transmission amount estimation unit 205 (data transmission amount estimation process) is not limited to the implementation of the subroutine.

FIG. 4 is a flow chart illustrating an example of an operation procedure of the data transmission amount estimation process in the transmission amount estimation unit 205 in step S101 of FIG.

In the first embodiment, it is assumed that the amount of data transmitted from the buffer 202 to the wireless terminal 10 with the identification number i and the wireless resource allocation index M (i, k) have a positive correlation.

First, the transmission amount estimation unit 205 obtains the data transmission amount D (i) from the buffer 202 to the wireless terminal from the past history of the wireless terminal with the identification number i (step S102).

Next, the transmission amount estimation unit 205 calculates the data transmission amount D _out (i) from the buffer 202 to the wireless terminal after changing the wireless parameters related to the allocation of wireless resources for the wireless terminal 10 (step S103).

The transmission amount estimation unit 205 calculates the data transmission amount from the buffer 202 to the wireless terminal 10 after changing the wireless parameters related to the allocation of wireless resources to the wireless terminal 10 based on the following mathematical formula (5). In the formula (5), the value of the elapsed time t (i) of the packet sent from the source to the wireless terminal (identification number = i) is larger than { _Treq (i) _-Tthresh (i)}. Therefore, when it becomes { _Treq (i) _-Tthresh (i)} or less, that is, the value of the radio parameter M _Delay (i) relating to the allocation of the radio resource of the radio terminal (identification number = i) is from 0. The data transmission amount D _out (i) from the buffer 202 to the wireless terminal (identification number = i) when the value is changed to a.

・・・（５）

... (5)

In formula (5)
The D _out (i) on the left side is the data destined for the radio terminal from the buffer 202 per time Δt (i) when the radio parameter M _Delay (i) related to the allocation of radio resources in the radio terminal with the identification number i is changed. The transmission amount [unit: bit].
The D (i) on the right side is the buffer 202 addressed to the wireless terminal at the time t (i) derived from the past history (before the wireless parameter M _Delay (i) is changed) of the wireless terminal having the identification number i. Data inflow [unit: bit].
The coefficient β on the right side is a coefficient that can be set arbitrarily. Although not particularly limited, in this embodiment, β = 1.
Alpha _Delay of paragraph 1 alpha _Delay · a of the right side of the molecule is alpha _Delay of the equation (1), a is the in Equation (2), t (i) ≧ T req (i) -T thresh It is a value of M _Delay in the case of (i). The numerator and denominator α _Type and M _Type (i) are the above formula (1) and the above formula (3), and the numerator and denominator α _SINR and M _SINR (i) are the above formula (1) and the above formula (4). ) Corresponds.

In the above formula (5), when the values M (i, k) (molecule) when M _Delay (i) is changed to a and M _Delay (i) are 0 in the above formula (1). By multiplying the value of M (i, k) (denominator) by D (i) × {Δt (i) / t (i)}, M _Delay (i) is changed from 0 to a. The data transmission amount D _out (i) from the buffer 202 at the time Δt (i) is obtained.

FIG. 5 is a flow chart illustrating an operation procedure in which the inflow amount control unit 206 of the radio base station 20 controls the inflow amount of data flowing into the buffer 202 of the radio base station 20 in the first embodiment.

After executing the operations shown in FIGS. 3 and 4, the radio base station 20 has a radio link established with the radio base station 20, and the radio parameter M relating to the allocation of radio resources in the radio base station 20. The operation shown in FIG. 5 is executed for the wireless terminal 10 having the identification number i in which the change in the _Delay is detected. Hereinafter, the operation of the inflow amount control unit 206 of the radio base station 20 of FIG. 2 will be described with reference to FIG.

The inflow amount control unit 206 of the wireless base station 20 uses the data transmission amount of the wireless terminal 10 calculated by the transmission amount estimation unit 205 and the data storage amount of the wireless terminal 10 managed by the buffer 202 to be used in the wireless terminal 10. The amount of data flowing into the buffer 202 is calculated (step S201).

The formula for calculating the amount of data inflow into the buffer 202 by the inflow amount control unit 206 with respect to the wireless terminal 10 is given by, for example, the following formula (6).

・・・（６）

... (6)

In the above formula (6)
The D _in (i) on the left side is the amount of data flowing into the buffer 202 for the wireless terminal 10 having the identification number i.
The B _target (i) on the right side is a target value of the amount of data stored to the wireless terminal 10 having the identification number i managed by the buffer 202 of the wireless base station 20.
B (i) is the amount of data (data storage amount) addressed to the wireless terminal 10 of the identification number i stored in the buffer 202 of the wireless base station 20 at the current time t.
D _out (i) is the amount of data transmitted from the buffer 202 addressed to the wireless terminal 10 having the identification number i.
r (i) is the amount of data per unit time addressed to the wireless terminal 10 of the identification number i that has flowed into the buffer 202. When r (i) changes depending on time, it is expressed as r (i, t), but for simplicity, it is expressed as r (i).

In the above formula (6), the second term (.) On the right side indicates the time Δt for the data storage amount B (i) addressed to the wireless terminal 10 in the buffer 202 at the current time t with respect to the wireless terminal 10 having the identification number i. Data transmission from the buffer 202 to the wireless terminal 10 from the value obtained by adding the amount of data (the integrated value of r (i) of the time Δt from t to t + Δt) that has flowed into the buffer 202 during The value obtained by subtracting the amount D _out (i) is, for example, the amount of data stored in the buffer 202 at time t + Δt addressed to the wireless terminal 10.

The value obtained by subtracting the amount of data stored for the wireless terminal 10 in the buffer 202 of the second paragraph (・) from the target value B _target (i) of the first term on the right side of the above mathematical formula (6) is the wireless terminal to the buffer 202. The amount of data inflow to 10 is D _in (i) (the left side of the above formula (6)).

The inflow amount control unit 206 of the wireless base station 20 executes the process described in step S201 of FIG. 5 for all the wireless terminals 10 having a wireless link established with the wireless base station 20, and then terminates the operation. To do.

In the above mathematical formula (6), r (i), which is the amount of data per unit time addressed to the wireless terminal 10 of the identification number i flowing into the buffer 202, may be the most recently observed value. In this case, the integral of the third term in parentheses on the right side of the above mathematical formula (6) is given by r (i) × Δt.

Alternatively, in the above formula (6), r (i) may be the average value of the values observed at any time before the current time. Alternatively, r (i) is data per unit time addressed to the wireless terminal 10 of the identification number i that has flowed into the buffer 202 by using, for example, the least squares method with respect to the value observed at an arbitrary time before the current time. An approximate curve (linear equation) showing the relationship between the quantity and time may be obtained and used as a value after a predetermined time has elapsed, which is derived from the approximate curve (for example, linear interpolation), or after a predetermined time has elapsed from the current time. It may be the average value of the values up to. In this case, the integral of the third term in parentheses on the right side of the above mathematical formula (6) is given by r (i) × Δt. Alternatively, r (i) may be the approximate curve that changes with time. In this case, the integration of the third term in () on the right side of the mathematical formula (6) is calculated by, for example, numerical integration on the information processing device of the radio base station 20.

Alternatively, in the above formula (6), r (i) is the amount of data per unit time addressed to the wireless terminal 10 of the identification number i that has flowed into the buffer 202 from the value observed at an arbitrary time before the current time. It may be a value after a predetermined time elapses, which is derived from the probabilistic diffusion by obtaining a stotic diffusion (probabilistic diffusion) with respect to time, or as an average value of values from the current time to a predetermined time. May be good. Alternatively, r (i) may be a function of the stochastic diffusion.

Further, in the above formula (6), if the calculation result on the right side is less than 0, D _in (i) may be set to 0.

FIG. 6A is a flow chart illustrating an example of an operation procedure in which the inflow amount control unit 302 of the server device 30 of FIG. 2 controls the data inflow amount destined for the wireless terminal 10. When the server device 30 of FIG. 2 receives information regarding the amount of data flowing into the buffer 202 for the wireless terminal 10 having the identification number i from the wireless base station 20, the server device 30 of FIG. 6 (A) refers to the wireless terminal 10. Perform the operations described in.

The inflow amount control unit 302 of the server device 30 receives information on the amount of data inflow into the buffer 202 addressed to the wireless terminal 10 of the identification number i notified from the wireless base station 20 to the buffer 202 addressed to the wireless terminal 10. It is determined whether or not the data inflow amount is 0 or more (step S301).

When the amount of data flowing into the buffer 202 for the wireless terminal 10 is a positive value (YES branch in step S301), the inflow amount control unit 302 of the server device 30 uses the data in the buffer 202 for the wireless terminal 10 as the data. Data corresponding to the amount of data inflow is added and transmitted to the radio base station 20 (step S302).

For example, the inflow amount control unit 302 of the server device 30 expands the TCP congestion window until the number of TCP packets corresponding to the data inflow amount is transmitted, thereby additionally transmitting data corresponding to the data inflow amount. It may be realized.

The inflow amount control unit 302 of the server device 30 may obtain the number of TCP packets when additionally transmitting data corresponding to the data inflow amount, for example, by using the calculation formula of the following formula (7). ..

・・・（７）

... (7)

In the above formula (7)
N _TCP is the number of TCP packets corresponding to the amount of data inflow to the wireless terminal 10 (identification number = i) into the buffer 202 of the wireless base station 20 (D _in (i) _{in the} above equation (6)). ..

The MSS [unit: bit] is the maximum segment size (Maximum Segment Size) of TCP. In addition, MSS represents the maximum length of data that can be transferred in one segment in TCP (however, the header size of TCP is not included).

は、Ｃｅｉｌｉｎｇ（天井）関数であり、実数ｘを超えない最大の整数ｎを表す（Ｚは整数を表す）。

Is a ceiling function and represents the largest integer n that does not exceed the real number x (Z represents an integer).

Referring to FIG. 6A, when the amount of data inflow to the buffer 202 of the radio base station 20 in FIG. 2 to the wireless terminal 10 is not a positive value (NO branch in step S301), the inflow of the server device 30 The quantity control unit 302 does not perform the process of step S302.

The inflow amount control unit 302 of the server device 30 executes the above operation for each wireless terminal 10 that has received information regarding the amount of data inflow from the inflow amount control unit 206 of the radio base station 20 to the buffer 202. After that, the inflow amount control unit 302 of the server device 30 ends the operation described in FIG. 6A.

Alternatively, in the inflow amount control unit 302 of the server device 30, as shown in FIG. 6B, when the data inflow amount of the wireless terminal 10 into the buffer 202 of the wireless base station 20 of FIG. 2 is not a positive value. (NO branch in step S301), the inflow amount control unit 302 may suppress data transmission to the wireless terminal 10 (step S303).

In this case, the inflow amount control unit 302 of the server device 30 stops the transmission to the wireless terminal 10 for the time ( _tstop ) calculated from the following mathematical formula (8) to transmit the data to the wireless terminal 10. Suppression may be achieved.

・・・（８）

... (8)

In the above formula (8)
R _TCP (i) is the most recent TCP throughput at the wireless terminal 10 with identification number i. Note that R _TCP (i) may be the average value of TCP throughput in the wireless terminal 10 with the identification number i observed at an arbitrary time before the current time.

Alternatively, in the above formula (8), R _TCP (i) uses the least square method from the TCP throughput of the wireless terminal 10 of the identification number i observed at an arbitrary time before the current time, and the wireless terminal 10 of the identification number i. Approximate curve (linear equation) showing the relationship between TCP throughput and time is obtained, and the wireless terminal with identification number i after a predetermined time has elapsed from the current time, which is derived from the approximate curve (or derived by linear interpolation). It may be the TCP throughput at 10, or it may be the average value of the TCP throughput at the wireless terminal 10 of the identification number i from the current time to the lapse of a predetermined time.

Alternatively, in the above formula (8), the R _TCP (i) is the time of the TCP throughput in the wireless terminal 10 of the identification number i from the TCP throughput of the wireless terminal 10 of the identification number i observed at an arbitrary time before the current time. It may be the TCP throughput in the wireless terminal 10 of the identification number i after a lapse of a predetermined time from the current time, which is derived from the stochastic diffusion by predicting the probabilistic spread (stochastic diffusion). It may be the average value of TCP throughput in the wireless terminal 10 of the identification number i after a lapse of a predetermined time from the time.

Further, the additional transmission of data corresponding to the amount of data inflow of the wireless terminal 10 in step S302 of FIGS. 6A and 6B increases the enlargement rate of the congestion window when the TCP ACK packet is received. It may be realized by.

The suppression of data transmission to the wireless terminal 10 in step S303 of FIG. 6B may be realized by reducing the enlargement ratio of the congestion window when the TCP ACK packet is received.

As described above, according to the first embodiment of the present invention, the amount of data leaked to the buffer, which is expected after changing the radio parameters related to the allocation of radio resources, is calculated and transferred to the buffer of the radio base station. By controlling the amount of data inflow, overflow or underflow of the buffer can be avoided. Therefore, it is possible to avoid a decrease in TCP throughput and improve the user's experience quality (QoE).

<Second embodiment>
Next, an exemplary second embodiment of the present invention will be described. The system configuration, the radio base station, and the server device configuration of the second embodiment are the same as those of the first embodiment described with reference to FIGS. 1 and 2, respectively. In the second embodiment, the processing operation of the transmission amount estimation unit 205 of the radio base station 20 of FIG. 2 is different from the processing operation of the transmission amount estimation unit 205 of the first embodiment described with reference to FIG. doing. Hereinafter, the description of the system configuration, the configuration of the radio base station 20, and the like will be omitted, and the operation of the transmission amount estimation unit 205 of the radio base station 20 will be mainly described.

[Explanation of operation]
The operation procedure for optimizing the amount of data flowing into the buffer 202 of the radio base station 20 when the radio base station 20 changes the radio parameters related to the allocation of radio resources will be described.

FIG. 7 is a flow chart illustrating an example of an operation procedure in which the transmission amount estimation unit 205 of the radio base station 20 shown in FIG. 2 estimates the data transmission amount of each radio terminal 10 after the radio parameters related to the allocation of radio resources. Is. FIG. 7 shows that the radio base station 20 targets all the radio terminals 10 for which a radio link has been established with the radio base station 20 after the change detection unit 204 detects a change in the radio parameters related to the allocation of radio resources. Perform the operations described in. The operation of the transmission amount estimation unit 205 of the radio base station 20 will be described below with reference to FIGS. 2 and 7.

The transmission amount estimation unit 205 of the wireless base station 20 refers to the wireless terminal 10 having a wireless link established with the wireless base station 20 as a “priority wireless terminal” and a “non-priority wireless terminal” which is another wireless terminal 10. It is classified into (step S111).

The priority radio terminal is a radio terminal 10 that is expected to increase the allocation of radio resources due to the radio parameters related to the changed radio resource allocation in the communication control unit 203 of the radio base station 20.

In the second embodiment, as an example, the priority radio terminal is a radio terminal 10 (identification) in which the value of the radio parameter (M _Delay (i)) related to the allocation of radio resources calculated by the above formula (2) is a. Number = i). That is, the allowable delay _{T req} (i) the elapsed time t (i) obtained by subtracting the time of the packet from the _packet: in the radio terminal 10 T req (i) -t (i ) becomes the threshold _{T thresh} (i) below is there.

Next, the transmission amount estimation unit 205 calculates the expected value of the radio section throughput after changing the radio parameters related to the allocation of radio resources for each radio terminal 10 classified as the priority radio terminal (step S112).

In the transmission amount estimation unit 205, in order to calculate the expected value of the radio section throughput after the radio parameter (M _Delay (i)) related to the allocation of radio resources to the radio terminal 10 is changed from 0 to a, the following Formula (9) is used.

Here, the wireless terminal 10 is a wireless terminal classified as a priority wireless terminal, and is a wireless terminal that does not calculate the expected value of the wireless section throughput after changing the wireless parameters related to the allocation of wireless resources.

For the radio terminal 10 that has already calculated the expected value of the radio section throughput after changing the radio parameter related to the allocation of radio resources as the priority radio terminal, the calculated expected value shall be used.

In the formula (9), it is assumed that the radio section throughput and the radio resource allocation index have a positive correlation, and the expected value of the radio section throughput after changing the radio parameters related to the radio resource allocation is calculated.

・・・（９）

... (9)

In the above formula (9)
E (i) on the left side is an expected value of the radio section throughput after changing the radio parameters related to the allocation of radio resources in the priority radio terminal of the identification number i.
R (i) on the right side is the most recent radio section throughput of the priority radio terminal having the identification number i.
Alpha _Delay of a molecule, the above equation (1), a is a value of _{M Delay} (i) in the case of _{t (i) ≧ T req (} i) -T thresh (i) In the above equation (2),
The numerator and denominator α _Type and M _Type (i) are the above formula (1) and the above formula (3),
The numerator and denominator α _SINR and M _SINR (i) correspond to the above mathematical formulas (1) and (4).
β is a coefficient that can be set arbitrarily, and is set to 1 in the present embodiment.

Next, the transmission amount estimation unit 205 requests the required radio resource, which is a radio resource necessary for realizing the expected value of the radio section throughput after changing the radio parameter calculated in step S112, for each radio terminal 10 classified as the priority radio terminal. Is calculated (step S113).

The following mathematical formula (10) is a calculation formula for the transmission amount estimation unit 205 to obtain the required radio resource. In this embodiment, the radio resource is a resource block.

・・・（１０）

... (10)

In the above formula (10)
N _recRB (i) is a radio resource (number of resource blocks) required to realize the expected value of the radio section throughput after changing the radio parameter related to the allocation of the radio resource in the priority radio terminal of the identification number i.
E (i) is an expected value of the radio section throughput after the radio parameter related to the allocation of radio resources in the priority radio terminal of the identification number i calculated by using the above formula (9) is changed.
CQI (i) is the latest Wideband CQI in the priority radio terminal of identification number i.
MCS (.) Is a function that converts CQI into MCS (Modulation and Coding Scheme).
TBS (.) Is a function for deriving TBS (Transport Block Size) from MCS and the number of resource blocks.
In the present embodiment, in the above formula (10), the number of resource blocks is calculated as 1.

In LTE, data of layer 2 or higher is managed in units called transport blocks (7-byte header). The transport block is divided into resource blocks (RB) units and accommodated in subframes (frame length 1 ms). At each TTI (Transmission Time Interval: transmission time interval), one transport block is generated for each wireless terminal to which the RB is assigned. The size of the transport block is determined by the number of physical resource blocks and the MCS. In the above formula (10), the size of the transport block is calculated assuming that the number of resource blocks is 1. In LTE, a short TTI such as 1 [ms] is adopted in order to realize a high data rate. 1000 [TTI / sec] is for converting the TTI in milliseconds (mllissecond) units into seconds (seconds). The above formula (10) is based on the assumption that one resource block is required for one transport block transmission, and the expected value of the wireless section throughput (communication speed: bps) is divided by the transport block size (converted to bps). , The number of wireless resource blocks is calculated.

Subsequently, the transmission amount estimation unit 205 of the radio base station 20 uses the total radio resource which is the radio resource possessed by the radio base station 20 and the requested radio resource N _reqRB (i) calculated in step S113 to be non-priority. The remaining wireless resource, which is a wireless resource that can be allocated to the wireless terminal, is calculated (step S114).

In this embodiment, the total radio resource is the number of resource blocks determined from the system bandwidth. The following formula (11) is a formula for calculating the remaining radio resources in the present embodiment.

・・・（１１）

... (11)

In the above formula (11)
_NRB is the number of resource blocks determined from the system bandwidth.
N _{restRB on the} left side is the number of resource blocks that can be allocated to the non-priority wireless terminal.
N _{prior UE} is the number of priority wireless terminals.
MAX [・] is a function that returns the maximum value of the argument as a return value. If the value obtained by subtracting the sum from the N _RB are each request radio resources of the priority radio terminal resource block number _N reqRB _(i) is negative, returns 0 if the value is positive or zero, and returns the value ..

After that, the transmission amount estimation unit 205 of the radio base station 20 calculates the expected value of the radio section throughput after changing the radio parameters related to the allocation of radio resources for each radio terminal 10 classified as a non-priority radio terminal (step). S115).

In the following formula (12), the transmission amount estimation unit 205 of the radio base station 20 calculates the expected value E (i) of the radio section throughput after changing the radio parameters related to the allocation of radio resources in the non-priority radio terminal i. It is a formula for.

・・・（１２）

... (12)

In the above formula (12), for TBS, which is the number of transmission bits per unit of the allocated radio resource, the expected value of the radio resource allocated to each non-priority radio terminal is η (η is per non-priority radio terminal). The expected value E (i) of the radio section throughput is derived based on the resource block).

はｆｌｏｏｒ（床）関数である（Ｚは整数）。

は、ｃｅｉｌｉｎｇ（天井）関数である。

の関係が成り立つ。

Is a floor function (Z is an integer).

Is the ceiling function.

The relationship holds.

TBS (MCS (CSI (i), floor (η))) corresponding to MCS (CSI (i), floor (η)) and TBS (MCS) corresponding to MCS (CSI (i), ceiling (η)) (CSI (i), ceiling (η))), internal division ratio (ceiling (η) -η): {1- (ceiling (η) -η)}
The TBS corresponding to η is obtained by interpolating with.

In the above mathematical formula (12), η is calculated using the following mathematical formula (13).

・・・（１３）

... (13)

In the above formula (13), N _{nprior UE} is the number of non-priority wireless terminals. N _restRB is derived based on the above mathematical formula (11).

After that, the transmission amount estimation unit 205 of the radio base station 20 determines the expected value E (i) of the radio section throughput after the radio parameters related to the allocation of radio resources calculated in step S112 or step S115 are changed. Is used to calculate the amount of data transmitted from the buffer 202 to each wireless terminal 10 (step S116).

The following mathematical formula (14) is a mathematical formula used by the transmission amount estimation unit 205 of the radio base station 20 to calculate the data transmission amount from the buffer 202 to the radio terminal 10.

・・・（１４）

... (14)

In the above formula (14)
D _out (i) on the left side is the amount of data transmitted from the buffer 202 to the wireless terminal with the identification number i. Also,
t is the current time, and Δt is a predetermined time that can be arbitrarily set. In the present embodiment, Δt is the allowable delay _Tthresh (i) used in the mathematical formula (2). The expected value E (i) of the throughput of the radio section after changing the radio parameter for the priority radio terminal or the non-priority radio terminal is integrated over the period from time t to t + Δt.

With the end of step S116, the transmission amount estimation unit 205 of the radio base station 20 ends the operation.

In the above mathematical formula (9), R (i) may be the average value of the radio section throughput observed at an arbitrary time before the radio parameter change related to the allocation of radio resources in the priority radio terminal of the identification number i.

Alternatively, in the above formula (9), R (i) uses the minimum square method from the radio section throughput observed at an arbitrary time before the radio parameter change related to the allocation of radio resources in the priority radio terminal of the identification number i. An approximate curve (linear equation) showing the relationship between the radio section throughput and time may be obtained, and the radio section throughput may be obtained from the approximate curve after a predetermined time has elapsed after changing the radio parameters related to the allocation of radio resources. It may be the average value of the radio section throughput from the change of the radio parameter related to the allocation of the radio resource to the lapse of a predetermined time.

Alternatively, in the above formula (9), R (i) is the radio section throughput and time from the radio section throughput observed at an arbitrary time before the radio parameter change related to the allocation of radio resources in the priority radio terminal of the identification number i. It may be the wireless section throughput after a predetermined time elapses after the radio parameter change related to the radio resource allocation, which is derived from the stochastic spread, and after the radio parameter change related to the radio resource allocation. It may be the average value of the radio section throughput up to the lapse of a predetermined time.

Further, in the above formula (10), the CQI (i) may be the average value of the Wideband CQI observed at an arbitrary time before the radio parameter change related to the allocation of radio resources in the priority radio terminal of the identification number i.

Alternatively, in the above equation (10), the CQI (i) uses the least squares method from the Wideband CQI observed at an arbitrary time before the change of the radio parameter related to the allocation of the radio resource in the priority radio terminal of the identification number i, and the Wideband. An approximate curve (linear equation) showing the relationship between CQI and time may be obtained, and may be used as a Wideband CQI derived from the approximate curve after a predetermined time has elapsed after changing the radio parameters related to the allocation of radio resources. Alternatively, in the above formula (10), the CQI (i) may be the average value of the Wideband CQI from the change of the radio parameter related to the allocation of the radio resource to the lapse of a predetermined time.

Alternatively, in the above formula (10), the CQI (i) is a probability related to the Wideband CQI and the time from the Wideband CQI observed at an arbitrary time before the radio parameter change related to the allocation of the radio resource in the priority radio terminal of the identification number i. It may be a Wideband CQI after a predetermined time has passed after the radio parameter change related to the radio resource allocation, which is derived from the stochastic spread, and a predetermined time has passed since the radio parameter change related to the radio resource allocation. It may be the average value of the later Wideband CQI.

In addition, in the above formula (10), CQI (i) is a value obtained by averaging the CQI _inst (i, k) of each resource block used in the above formula (4) in all resource blocks instead of the above Wideband CQI. You may use it. Alternatively, the CQI of any resource block from the CQI _inst (i, k) of each resource block used in the above formula (4) may be used.

Further, in the above formula (10), instead of using the MCS (.), The latest MCS in the priority radio terminal of the identification number i may be used, and the radio related to the allocation of radio resources in the priority radio terminal of the identification number i. It may be the average value of MCS observed at an arbitrary time before changing the parameter.

Alternatively, in the above equation (10), instead of using the MCS (.), The least squares method is used from the MCS observed at an arbitrary time before the radio parameter change related to the allocation of radio resources in the priority radio terminal of the identification number i. , An approximate curve (linear equation) showing the relationship between MCS and time may be obtained, and the MCS may be derived from the approximate curve and after a predetermined time has elapsed after changing the radio parameters related to the allocation of radio resources.

Alternatively, in the above formula (10), it may be the average value of MCS from the change of the radio parameter related to the allocation of the radio resource to the lapse of a predetermined time.

Alternatively, in the above formula (10), instead of using the MCS (.), The MCS and the time are related from the MCS observed at an arbitrary time before the radio parameter change related to the allocation of the radio resource in the priority radio terminal of the identification number i. The MCS may be obtained after a predetermined time has elapsed after the radio parameter change related to the radio resource allocation, which is derived from the stochastic spread, and the predetermined time elapses after the radio parameter change related to the radio resource allocation. It may be the average value of MCS until later.

Further, in the above formula (10), instead of using TBS (.), The latest TBS in the priority wireless terminal having the identification number i may be used.

In the above formula (10), it may be the average value of TBS observed at an arbitrary time before changing the radio parameter related to the allocation of radio resources in the priority radio terminal of the identification number i.

Alternatively, in the above equation (10), instead of using TBS (・), the least squares method is used from the MCS observed at an arbitrary time before the radio parameter change related to the allocation of radio resources in the priority radio terminal of the identification number i. , An approximate curve (linear equation) showing the relationship between TBS and time may be obtained, and the MCS derived from the approximate curve may be used as the MCS after a predetermined time has elapsed after changing the radio parameters related to the allocation of radio resources.

In the above formula (10), it may be the average value of TBS from the change of the radio parameter related to the allocation of the radio resource to the lapse of a predetermined time. Alternatively, instead of using the TBS (.), The probabilistic diffusion regarding the TBS and the time is obtained from the TBS observed at an arbitrary time before the radio parameter change related to the allocation of the radio resource in the priority radio terminal of the identification number i. It may be an MCS derived from stochastic diffusion after a predetermined time elapses after the radio parameter change related to the radio resource allocation, and the average value of TBS from the radio parameter change related to the radio resource allocation to the elapse of the predetermined time. May be.

Each of the above modified examples may be applied in the above mathematical formula (12).

Further, in the above mathematical formula (9), β may be derived from the correlation between the radio section throughput and the radio resource allocation index.

In the second embodiment of the present invention, the operation procedure for controlling the amount of data inflow that the inflow amount control unit 206 of the radio base station 20 flows into the buffer 202 of the radio base station 20 is described with reference to FIG. It is the same as the first embodiment.

The transmission amount estimation unit 205 of the radio base station 20 executes the operations of steps S111 to S116 shown in FIG. 7, and then for each of all the radio terminals 10 for which a radio link is established with the radio base station 20. The operation described in 5 is executed.

The inflow amount control unit 206 of the radio base station 20 uses the data transmission amount of the radio terminal 10 calculated by the transmission amount estimation unit 205 and the data storage amount of the radio terminal 10 managed by the buffer 202 to the buffer 202. The amount of data inflow addressed to the wireless terminal 10 is calculated (step S201).

The inflow amount control unit 206 of the radio base station 20 uses, for example, the following formula (15) as a calculation formula of the data inflow amount D _in (i) destined for the radio terminal 10 into the buffer 202. Since the mathematical formula (15) is the same as the mathematical formula (6) described above, the description thereof will be omitted.

・・・（１５）

... (15)

The inflow amount control unit 206 of the wireless base station 20 executes the process described in step S201 of FIG. 5 for all the wireless terminals 10 for which a wireless link has been established with the wireless base station 20, and then FIG. Ends the operation of.

In the above mathematical formula (15), r (i), which is the amount of data per unit time addressed to the wireless terminal 10 of the identification number i flowing into the buffer 202, may be the value observed most recently, and is before the current time. It may be the average value of the values observed at any time of. Alternatively, r (i) is the amount and time of data per unit time addressed to the wireless terminal 10 of the identification number i that has flowed into the buffer 202 using the least squares method from the value observed at an arbitrary time before the current time. An approximate curve (linear equation) showing the relationship between the two may be obtained, and the value may be derived from the approximate curve after a predetermined time has elapsed, or may be an average value of the values from the current time to the elapse of a predetermined time. Alternatively, r (i) may be the approximate curve. Alternatively, r (i) is a stochastic diffusion (Stochastic) regarding the amount of data per unit time and the time of the identification number i flowing into the buffer 202 from the value observed at an arbitrary time before the current time to the wireless terminal 10. Diffusion) may be obtained and used as a value after a predetermined time has elapsed, which is derived from the stochastic diffusion, or may be an average value of values from the current time to a predetermined time. Alternatively, r (i) may be a function of the stochastic diffusion.

Further, as in the first embodiment, when the calculation result on the right side is less than 0 in the above mathematical formula (15), the data inflow amount D _in (i) may be set to 0.

In the second embodiment, the operation procedure in which the inflow amount control unit 302 of the server device 30 of FIG. 2 controls the data inflow amount of the wireless terminal 10 is described with reference to FIGS. 6 (A) and 6 (B). It is the same as the first embodiment described above. When the server device 30 receives information related to the data inflow amount of the wireless terminal 10 from the wireless base station 20, the server device 30 executes the operation shown in FIG. 6A or FIG. 6B for each wireless terminal 10. To do.

First, the inflow amount control unit 302 of the server device 30 determines whether or not the data inflow amount of the wireless terminal 10 is 0 or more from the information related to the data inflow amount of the wireless terminal 10 notified from the wireless base station 20. (Step S301).

When the amount of data inflow from the buffer 202 addressed to the wireless terminal 10 is a positive value (YES branch in step S301), the inflow amount control unit 302 of the server device 30 indicates the amount of data inflow to the wireless terminal 10. Data is additionally transmitted (step S302). In the present embodiment, the inflow amount control unit 302 realizes additional transmission of data corresponding to the data inflow amount by expanding the TCP congestion window until the number of packets corresponding to the data inflow amount is transmitted. It shall be. Number of TCP packets N The _TCP calculation formula is given by the following formula (16). The mathematical formula (16) is the same as the mathematical formula (7) described above.

・・・（１６）

... (16)

On the other hand, when the amount of data inflow from the buffer 202 addressed to the wireless terminal 10 is not a positive value (NO branch in step S301), the inflow amount control unit 302 of the server device 30 does not perform the process of step S302.

The inflow amount control unit 302 executes the above operation for each wireless terminal 10 that has received the information related to the requested data inflow amount. After that, the inflow amount control unit 302 ends the operation described in FIG. 6A or FIG. 6B.

Further, as shown in FIG. 6B, when the data inflow amount of the wireless terminal 10 is not a positive value (step S301, NO branch), the inflow amount control unit 302 transmits data to the wireless terminal 10. It may be suppressed (step S303). In this case, the inflow amount control unit 302 of the server device 30 suppresses data transmission to the wireless terminal 10 by stopping transmission to the wireless terminal 10 for a time ( _tstop ) calculated from the mathematical formula (17). It may be realized. In the following equation (17), R _TCP (i) is the most recent TCP throughput at the wireless terminal 10 with identification number i. The mathematical formula (17) is the same as the mathematical formula (8) described above.

・・・（１７）

... (17)

In the above formula (17), R _TCP (i) may be the average value of TCP throughput in the wireless terminal 10 of the identification number i observed at an arbitrary time before the current time. Alternatively, R _TCP (i) uses the minimum square method from the TCP throughput of the wireless terminal 10 of the identification number i observed at an arbitrary time before the current time, and the TCP throughput and the time of the wireless terminal 10 of the identification number i. An approximate curve (linear equation) showing the relationship may be obtained, and the TCP throughput in the wireless terminal 10 of the identification number i after a lapse of a predetermined time from the current time, which is derived from the approximate curve (derived by linear interpolation), may be used. It may be the average value of TCP throughput in the wireless terminal 10 of the identification number i from the current time to the lapse of a predetermined time. Alternatively, R _TCP (i) is a probabilistic spread (probability) of the TCP throughput in the wireless terminal 10 of the identification number i from the TCP throughput of the wireless terminal 10 of the identification number i observed at an arbitrary time before the current time. It may be the TCP throughput in the wireless terminal 10 of the identification number i after a predetermined time has elapsed from the current time, which is derived from the stochastic diffusion by predicting the stochastic diffusion, and may be the TCP throughput after the predetermined time has elapsed from the current time. It may be the average value of TCP throughput in the wireless terminal 10 of the identification number i.

Further, the additional transmission of data corresponding to the data inflow amount of the wireless terminal 10 in step S302 may be realized by increasing the enlargement ratio of the congestion window when the TCP ACK packet is received.

The suppression of data transmission to the wireless terminal 10 in step S303 may be realized by lowering the enlargement ratio of the congestion window when the TCP ACK packet is received.

As described above, according to the second exemplary embodiment of the present invention, the expected value of the throughput of the radio section assumed after changing the radio parameter related to the allocation of the radio resource is calculated, and the expected value is calculated. By controlling the amount of data flowing into the buffer of the wireless base station by using it, it is possible to avoid overflow and underflow of the buffer, so that it is possible to avoid a decrease in TCP throughput and improve the user's experience quality (QoE).

Although the present invention has been described above with reference to the above-described embodiment, the present invention is not limited to the above-described embodiment. Various modifications that can be understood by those skilled in the art can be made within the scope of the present invention in the configuration and details of the present invention.

<Modification example>
For example, in the present embodiment, the function of the inflow amount control unit 206 of the radio base station 20 may be implemented in the inflow amount control unit 302 of the server device 30. In this case, the information notification unit 207 of the radio base station 20 manages the information related to the data transmission amount of the radio terminal 10 calculated by the transmission amount estimation unit 205 of the radio base station 20 and the buffer 202 of the radio base station 20. Information related to the amount of data stored in the wireless terminal 10 is notified to the server device 30.

Further, the transmission amount estimation unit 205 of the radio base station 20 may be provided in the server device 30. In this case, the information notification unit 207 of the radio base station 20 contains information related to the expected value of the radio section throughput after changing the radio parameters related to the allocation of radio resources calculated by the transmission amount estimation unit 205, and the buffer of the radio base station 20. The server device 30 is notified of the information related to the data storage amount of the wireless terminal 10 managed by 202.

Further, in the present embodiment, the change detection unit 204 changes the radio parameter in the communication control unit 203 by using the value M _Delivery (i) calculated by the above formula (2) as a radio parameter related to the allocation of radio resources. However, not limited to this case, it is also possible to detect changes in radio parameters related to the allocation of radio resources.

For example
・ CQI, RSRP, RSRQ, reported from wireless terminal 10.
-Transmission power allocated to the reference signal,
-Transmission power allocated to the downlink data channel,
・ Transmission mode,
・ Antenna configuration actually used,
・ Transmission beam formed by beamforming,
・ Carrier frequency used for wireless communication,
・ Wireless line quality and traffic load related to the carrier frequency,
・ Component carriers used in carrier aggregation,
・ Wireless terminal category,
・ RAT
The change of the radio parameter may be detected as the radio parameter related to the allocation of the radio resource.

In this case, the transmission amount estimation unit 205 calculates the data transmission amount of each wireless terminal 10 based on the radio parameter to be changed.

Furthermore, in the present embodiment, the change detection unit 204 may detect a case where the radio parameter related to the allocation of radio resources changes after a lapse of a predetermined time. In this case, before the radio parameters related to the allocation of radio resources are actually changed, the transmission amount estimation unit 205, the inflow amount control unit 206, the information notification unit 207, and the inflow amount control unit 302 operate to perform data. The transmission amount is transmitted before the radio parameters related to the allocation of radio resources are changed.

Then, in the present embodiment, the change detection unit 204 of the wireless base station 20 may be provided in the wireless terminal 10. For example, the change detection unit 204 sets CQI, RSRP, and RSRQ measured by the wireless terminal 10 as wireless parameters related to the allocation of wireless resources, and sets a state in which the wireless parameters are equal to or less than a predetermined value as wireless parameters related to the allocation of wireless resources. May be detected as a changed state.

In this case, the change detection unit 204 provided in the wireless terminal 10 notifies the wireless base station 20 of the change in the wireless parameters related to the allocation of wireless resources. The notification to the radio base station 20 includes the existing information transmitted between the radio terminal 10 and the radio base station 20, such as an RRC message (for example, RRC Connection Section Complete, RRC Connection Reconnection Report, Measurement Report). You may notify. Alternatively, a new information message may be defined to perform the notification, and the new information message may be used for notification.

The modified example including the above changes can be similarly performed in the subsequent embodiments.

<Third embodiment>
Next, an exemplary third embodiment of the present invention will be described in detail with reference to the drawings. In the third embodiment, a relay device is arranged between the radio base station and the server device, and the relay device acquires the quality requirements for the application in the wireless terminal and flows data into the buffer of the radio base station. Control the amount. The application on the wireless terminal shall include, for example, an application program executed on the wireless terminal that affects the user's experience quality (QoE). Although not particularly limited, application programs include, for example.
・ Web browser,
・ Email program (mailer),
・ Location information display program,
・ Telephone program,
・ Short message service program,
・ Streaming service program,
・ Multimedia service program,
・ Gaming program,
・ Includes social networking service programs.

[Description of configuration]
FIG. 8 is a diagram schematically showing a configuration of a communication system according to an exemplary third embodiment of the present invention. Referring to FIG. 8, the communication system 1A has a radio base station 21 and a server instead of the radio base station 20 and the server device 30 as compared with the communication system 1 according to the first embodiment shown in FIG. The device 31 is provided. Further, the communication system 1A is newly provided with the relay device 40 as compared with the communication system 1 according to the first embodiment. In the following, with respect to the third embodiment, the description of the same elements as those of the first and second embodiments will be omitted as appropriate, and the configuration changed from the first and second embodiments will be mainly described.

The relay device 40 is arranged between the server device 31 and the radio base station 21. In the example of FIG. 8, the relay device 40 is arranged in the external network 52. The relay device 40 relays data transmitted or received between the server device 31 and the radio base station 21. At that time, the transmission of data to the wireless base station 21 (hence, the amount of data inflow to the wireless terminal 10 into the buffer of the wireless base station 21) is controlled based on the data inflow amount information from the wireless base station 21 and the like.

The relay device 40 and the server device 31 are configured to communicate with each other via an external network such as the Internet. Further, the relay device 40 and the wireless base station 21 are configured to communicate with each other via a communication line network.

Similar to the first embodiment, the communication line network 50 is composed of an external network such as the Internet and a mobile core network. For convenience of explanation, in FIG. 8, the communication system 1A is exemplified as a configuration including one each of a wireless terminal 10, a wireless base station 21, a server device 31, and a relay device 40. However, the number of wireless terminals 10 may be any number. Similarly, the number of radio base stations 21, the number of server devices 31, and the number of relay devices 40 may be any number.

In FIG. 8, the radio base station 21 includes an information processing device and a transceiver (transmitter and receiver) (not shown), similarly to the radio base station 20 according to the first embodiment. The information processing device includes a central processing unit (CPU) (not shown) and a storage device (memory and hard disk drive device (HDD)). The radio base station 21 may be configured to realize the functions described later by the CPU executing the program stored in the storage device.

In FIG. 8, the server device 31 is a device that provides various communication services to the wireless terminal 10 as in the server device 30 according to the first embodiment. Further, the server device 31 includes an information processing device (not shown) and a communication interface as in the server device 30 of the first and second embodiments. The information processing device includes a central processing unit (CPU) (not shown) and a storage device (memory and hard disk drive device (HDD)). The server device 31 may be configured to realize a function of providing various communication services to the wireless terminal 10 by the CPU executing a program stored in a storage device (not shown).

The relay device 40 includes an information processing device and a communication interface (not shown). The information processing device includes a central processing unit (CPU) (not shown) and a storage device (memory and hard disk drive device (HDD)). The relay device 40 may be configured to realize a function described later by the CPU executing a program stored in a storage device (not shown).

FIG. 9 is a diagram schematically showing the function of the communication system 1A of the third embodiment shown in FIG. In the following, the functions added and changed in the third embodiment will be described as compared with the first and second embodiments.

As shown in FIG. 9, the server device 31 does not have the function of the inflow amount control unit 302 of the server device 30 of FIG. 2, but includes the basic function unit 301.

The relay device 40 includes a basic function unit 401, an information acquisition unit 402, an information notification unit 403, and an inflow amount control unit 404.

As described above, the operation of the following functional units is realized by the central processing unit (CPU), the information processing device, the communication interface, and the storage device (memory and HDD) included in the relay device 40 operating in cooperation with each other. Will be done.

In FIG. 9, the basic functional unit 401 of the relay device 40 is, for example,
-A function of transmitting and / or receiving signals via the server device 31 and an external network such as the Internet.
A function of transmitting and / or receiving a signal via a communication line network with a wireless base station 21.
A function of measuring and managing the communication throughput (communication speed between the relay device 40 and the wireless terminal 10) at predetermined time intervals between the relay device 40 and the wireless terminal 10.
Etc.

The information acquisition unit 402 of the relay device 40 has a function of acquiring predetermined information about the application in each wireless terminal 10.

In the present embodiment, the predetermined information about the application is, for example, as the quality requirement information of the application.
-Request delay to satisfy the QoE of the application, and
-Required throughput to satisfy the QoE of the application,
including.

In the relay device 40, the information (quality requirement information) about the application acquired by the information acquisition unit 402 is used by the information notification unit 403.

In the relay device 40, the information information notification unit 403 has a function of notifying the wireless base station 21 of information (quality requirement information) about the application in each wireless terminal 10 acquired by the information acquisition unit 402 via the basic function unit 401. Has.

Notification of information (quality requirement information) about an application in a wireless terminal 10 to a wireless base station 21 is performed by concatenating the information with an IP (Internet Protocol) packet corresponding to the data addressed to the wireless terminal 10. It may be. In this case, the information may be added to the header area of the IP packet. Further, the TCP (Transmission Control Protocol) used in the upper layer of the IP may be used by concatenating the information with the TCP packet corresponding to the IP packet. Further, the information may be added to the header area of the TCP packet. Alternatively, instead of TCP, UDP (User Datagram Protocol) may be used to concatenate the information to the UDP packet corresponding to the IP packet. Further, the information may be added to the header area of the UDP packet. Alternatively, a new interface for notifying the information may be installed between the relay device 40 and the radio base station 21, and the information may be notified via the interface.

The inflow amount control unit 404 of the relay device 40 has the same function as the inflow amount control unit 302 of the server device 30 according to the first and second embodiments described with reference to FIG. That is, the inflow amount control unit 404 of the relay device 40 receives the data inflow amount information addressed to the wireless terminal (identification number = i) from the inflow amount control unit 206 of the radio base station 21 to the buffer 202, and the data inflow amount is calculated. If the value is positive, additional data corresponding to the amount of data inflow is additionally transmitted (step S302 in FIG. 6A). When the data inflow amount is 0 or a negative value, the additional data is not transmitted or is suppressed (step S303 in FIG. 6B). Further description of the inflow amount control unit 404 will be omitted (see the description of the inflow amount control unit 302 of the server device 30 of the first and second embodiments).

Compared with the radio base station 20 according to the first and second embodiments, the radio base station 21 has a communication control unit 213 and a transmission amount estimation unit instead of the communication control unit 203 and the transmission amount estimation unit 205. It has 215 functions. Hereinafter, the functions of the communication control unit 213 and the transmission amount estimation unit 215 in the radio base station 21 will be described.

In the wireless base station 21, the communication control unit 213 newly has a function of acquiring information (quality requirement information) regarding the application in the wireless terminal 10 notified from the relay device 40.

The communication control unit 213 of the radio base station 21 may be configured to have, for example, a DPI (Deep Packet Inspection) function. The DPI of the communication control unit 213 acquires information about the application running on the wireless terminal 10 from the IP packet corresponding to the data addressed to the wireless terminal 10 transmitted from the relay device 40. The DPI identifies the application, behavior, etc. by specifying the type of packet based on not only the header information of the packet but also the information of the payload (data part), and provides predetermined information about the application. get.

At this time, the communication control unit 213 of the wireless base station 21 may delete the information from the IP packet after acquiring the information about the application in the wireless terminal 10. Similarly, when a TCP packet or a UDP packet is used instead of the IP packet in the notification of the information about the application in the wireless terminal 10 to the wireless base station 21, the communication control unit 213 of the wireless base station 21 similarly uses the DPI. The information related to the application in the wireless terminal 10 may be acquired from the IP packet corresponding to the data addressed to the wireless terminal 10 transmitted from the relay device 40. Further, at this time, the communication control unit 213 of the wireless base station 21 may delete the information about the application from the packet after acquiring the information about the application in the wireless terminal 10.

Further, a new interface for notifying the information may be installed between the relay device 40 and the wireless base station 21, and the information related to the application in the wireless terminal 10 may be notified via the interface. In this case, the communication control unit 213 of the wireless base station 21 has a function of acquiring information via the interface, and acquires information (quality requirement information) about the application in the wireless terminal 10 notified via the interface. It may be configured.

Further, FIG. 2 shows that the communication control unit 213 of the wireless base station 21 uses the acquired information related to the application in the wireless terminal 10 in the wireless resource management function of the wireless base station in a general wireless communication system. It is different from the communication control unit 203 of the first and second embodiments described with reference to the above.

In the present embodiment, similarly to the first and second embodiments, the radio resource allocation index M (i, k) is calculated based on the above mathematical formulas (1) to (4). However, in the embodiment, the threshold value _{T thresh} (i) in the equation (2), a request delay for satisfying the application QoE in the radio terminal 10.

Further, the value a of M _Delivery (i) in the above mathematical formula (2) derives a correlation between the radio section throughput and the radio resource allocation index, and based on the correlation, the QoE of the application in the radio terminal 10 is calculated. You may set the value required to achieve the required throughput to satisfy.

The transmission amount estimation unit 215 of the radio base station 21 has a function of acquiring information about an application in the radio terminal 10 notified from the relay device 40.

The transmission amount estimation unit 215 of the radio base station 21 has a DPI (Deep Packet Inspection) function, and relates to an application in the radio terminal 10 from an IP packet corresponding to data addressed to the radio terminal 10 transmitted from the relay device 40. It may be configured to acquire information.

The transmission amount estimation unit 215 of the radio base station 21 may delete the information related to the application from the IP packet after acquiring the information related to the application in the wireless terminal 10.

Even when a TCP packet or a UDP packet is used instead of the IP packet in the notification of the information about the application in the wireless terminal 10 to the wireless base station 21, the transmission amount estimation unit 215 of the wireless base station 21 functions as a DPI. In addition, the information related to the application in the wireless terminal 10 may be acquired from the IP packet corresponding to the data addressed to the wireless terminal 10 transmitted from the relay device 40. Further, the transmission amount estimation unit 215 may delete the information about the application from the packet after acquiring the information about the application in the wireless terminal 10.

Further, a new interface for notifying the information may be installed between the relay device 40 and the wireless base station 21, and the information regarding the application in the wireless terminal 10 may be notified via the interface. In this case, the transmission amount estimation unit 215 of the wireless base station 21 may have a function of acquiring information via the interface, and may be configured to acquire information about an application in the wireless terminal 10 notified via the interface. ..

The transmission amount estimation unit 215 of the radio base station 21 has a function of estimating the data transmission amount from the buffer 202 to the radio terminal 10 by using the acquired information about the application in the radio terminal 10.

The data transmission amount from the buffer 202 to the wireless terminal 10 estimated by the transmission amount estimation unit 215 of the radio base station 21 is used by the inflow amount control unit 206.

[Explanation of operation]
Next, an operation procedure for optimizing the amount of data flowing into the buffer 202 of the radio base station 21 when the radio base station 21 changes the radio parameters related to the allocation of radio resources will be described.

FIG. 10 shows an example of an operation procedure in which the transmission amount estimation unit 215 of the radio base station 21 estimates the data transmission amount of each wireless terminal 10 in the third embodiment described with reference to FIGS. 8 and 9. It is a flow chart to explain. FIG. 10 shows that the radio base station 21 targets all radio terminals 10 for which a radio link has been established with the radio base station 20 after the change detection unit 204 detects a change in radio parameters related to the allocation of radio resources. Perform the operations described in.

Referring to FIG. 10, step S112 (calculation of the expected value of the wireless section throughput after changing the wireless parameter for the priority wireless terminal) in FIG. 7 is step S401 (calculating the required throughput of the application of the priority wireless terminal after changing the wireless parameter). It has been replaced with (set as the expected throughput value). In FIG. 10, step S111, step S113, step S114, step S115, and step S116 are the same as those in the second embodiment described with reference to FIG. 7. The operation of step S401 in FIG. 10 will be described below.

After the processing of step S101 (classification of priority wireless terminal and non-priority wireless terminal) is completed, the transmission amount estimation unit 215 of the wireless base station 21 applies the application in the wireless terminal 10 to each wireless terminal 10 classified as the priority wireless terminal. The required throughput for satisfying the QoE of is set as an expected value of the radio section throughput after changing the radio parameters related to the allocation of radio resources (step S401). That is, in step S401, the transmission amount estimation unit 205 satisfies the QoE of the application in the wireless terminal 10 instead of calculating the right side of the above mathematical formula (9) for each wireless terminal 10 classified as the priority wireless terminal. The required throughput for this is set as the expected value E (i) [bps] of the radio section throughput after changing the radio parameters related to the allocation of radio resources.

In the next step S113, the transmission amount estimation unit 205 of the radio base station 21 obtains the required radio resource, which is a radio resource necessary for realizing the expected value E (i) [bps] of the radio section throughput calculated in step S401. Calculate using the above formula (10).

The following steps are the same as in the second embodiment. That is, in step S114, the transmission amount estimation unit 215 of the radio base station 21 calculates the remaining radio resources using the above mathematical formula (11). In the next step S115, the expected value E (i) [bps] of the radio section throughput after changing the radio parameters for the non-priority radio terminal is calculated using the above formula (12). In the final step S116, the transmission amount estimation unit 215 of the radio base station 21 determines the expected value of the radio section throughput after the radio parameters related to the allocation of radio resources calculated in step S401 or step S115 are changed. For E (i), the data transmission amount D _out (i) from the buffer 202 for each wireless terminal 10 is calculated using the above mathematical formula (14).

According to an exemplary third embodiment of the present invention, the amount of data flowing into the buffer 202 of the radio base station 21 to the radio terminal 10 is controlled using the required throughput for satisfying the QoE of the application. There is. Therefore, the user's experience quality (QoE) can be improved as compared with the first and second embodiments.

<Fourth Embodiment>
Next, an exemplary fourth embodiment of the present invention will be described. The configuration of the wireless terminal 10, the wireless base station 21, the relay device 40, and the server device 31 in the communication system of the fourth embodiment of the present invention will be described with reference to FIGS. 8 and 9. It is substantially the same as the embodiment. FIG. 11 is a flow chart illustrating an example of an operation procedure of the transmission amount estimation unit 215 of the radio base station 21 according to the fourth embodiment. In the fourth embodiment, for example, the transmission amount estimation unit 215 of the radio base station 21 of FIG. 8 instead of executing the operation shown in FIG. 10 (a series of processes of steps S111, S401, and S113-S116). The operation described in FIG. 11 may be executed.

With reference to FIG. 11, step S401 in FIG. 10 is replaced by step S501, and steps S113 to S115 in FIG. 10 are replaced by steps S502 to S504. Hereinafter, the operation of the added steps S501 to S504 will be mainly described.

After the processing of step S101 (classification of priority radio terminal and non-priority radio terminal) is completed, the transmission amount estimation unit 215 of the radio base station 21 refers to each radio terminal 10 classified as a non-priority radio terminal in the radio terminal 10. The required throughput for satisfying the QoE of the application is set as an expected value of the radio section throughput after changing the radio parameters related to the allocation of radio resources (step S501). That is, in step S501, the transmission amount estimation unit 215 of the wireless base station 21 wirelessly determines the required throughput for satisfying the QoE of the application in the wireless terminal 10 for each wireless terminal 10 classified as a non-priority wireless terminal. Set as the expected value E (i) [bps] of the radio section throughput after changing the parameters.

Next, the transmission amount estimation unit 215 of the radio base station 21 determines the expected value E (i) [bps] of the radio section throughput after changing the radio parameters calculated in step S501 for each radio terminal 10 classified as a non-priority radio terminal. ] Is calculated using the above equation (10) (step S502). That is, in step S502, the N _reqRB (i) of the above formula (10) is the expected value E (i) [bps of the radio section throughput after changing the radio parameter related to the radio resource allocation in the non-priority radio terminal of the identification number i. ] Is a wireless resource necessary for the realization.

In the next step S503, the transmission amount estimation unit 215 of the radio base station 21 calculates the remaining radio resources using the following mathematical formula (18).

・・・（１８）

... (18)

The above formula (18) allocates the radio resources necessary for realizing the expected value of the radio section throughput after changing the radio parameters related to the radio resource allocation in the priority radio terminal in the above formula (11) to the radio resources in the non-priority radio terminal. Replaced with the radio resources required to realize the expected value of the radio section throughput after changing the radio parameters, and the total sum was replaced with the number of non-priority radio terminals from the number of priority radio terminals in the above formula (11). Is. That is, in the above formula (18), N _{restRB on} the left side is the number of resource blocks that can be allocated to the priority wireless terminal.
Right side of the N _RB is the number of resource blocks is determined from the system bandwidth.
N _recRB (i) on the right side is the number of resource blocks that can be allocated to the non-priority wireless terminal having the identification number i obtained in step S502.
N _{nprior UE} is the number of non-priority radio terminals.
MAX [・] is a function that returns the maximum value of the argument as a return value. If the value obtained by subtracting the sum from the N _RB are each request radio resources of the non-priority mobile station resource block number _N reqRB _(i) is negative, returns 0 if the value is positive or 0, the value return.

After that, the transmission amount estimation unit 215 of the radio base station 21 determines the expected value E (i) [bps] of the radio section throughput after changing the radio parameters related to the allocation of radio resources for each radio terminal 10 classified as the priority radio terminal. ] Is calculated (step S504).

In step S503, the transmission amount estimation unit 215 of the radio base station 21 calculates the expected value E (i) of the radio section throughput after changing the radio parameters related to the allocation of radio resources of the priority radio terminal by the above formula (12). ) Is used. However, in the present embodiment, the following mathematical formula (19) is used as the η in the mathematical formula (12) instead of the mathematical formula (13). As shown in the mathematical formula (19), η is a value _obtained by dividing the N _restRB calculated by using the above mathematical formula (18) by the number of priority wireless terminals N _{prior UE} .

・・・（１９）

... (19)

In the next step S116, the transmission amount estimation unit 215 of the radio base station 21 determines the expected value of the radio section throughput after the radio parameters related to the allocation of radio resources calculated in step S501 or step S504 are changed. For E (i), the data transmission amount D _out (i) from the buffer 202 for each wireless terminal 10 is calculated using the above mathematical formula (14).

According to an exemplary fourth embodiment of the present invention, when a wireless terminal 10 that is expected to increase the allocation of wireless resources is generated due to a change in wireless parameters related to the allocation of wireless resources, other than the wireless terminal 10. The allocation of wireless resources to the wireless terminal 10 can be increased while ensuring the minimum guaranteed rate of the wireless terminal 10.

Further, in the exemplary fourth embodiment of the present invention, the function of the relay device 40 may be the server device 31. That is, the server device 31 may include an information acquisition unit 402, an information notification unit 403, and an inflow amount control unit 404. Further, in this case, the relay device 40 is not an essential component.

<Fifth Embodiment>
Next, an exemplary fifth embodiment of the present invention will be described. In the third and fourth embodiments, in the communication system 1A shown in FIG. 8, the relay device 40 is arranged in the external network 52, but in the communication system 1B of the fifth embodiment, FIG. As shown in 12, the relay device 40 is arranged in the mobile core network 51. For example, the relay device 40 may be a P-GW (PDN (Packet Data Network) -Gateway) arranged in the EPC, or an S-GW (Serving-Gateway).

In this case, in the information notification unit 403 of the relay device 40, the notification of the information related to the application in the wireless terminal 10 to the wireless base station 21 is GTP (GPRS (General Packet Radio Service) corresponding to the data addressed to the wireless terminal 10. It may be performed by concatenating the information in the Tunneling Protocol) packet. Alternatively, the information may be added to the header area (GTP header) of the GTP packet.

Further, in the UDP used in the lower layer of the GTP, the information may be concatenated with the UDP packet corresponding to the GTP packet. Further, the information may be added to the header area of the UDP packet. Further, the IP used in the lower layer of the UDP may be performed by concatenating the information with the IP packet corresponding to the GTP packet. Further, it may be performed by adding the information to the header area of the IP packet.

In the fifth embodiment, a new interface for notifying the information may be installed between the relay device 40 and the radio base station 21, and the information may be notified via the interface. Further, in this case, the transmission amount estimation unit 215 of the wireless base station 21 does not require the function of the DPI, and from various packets corresponding to the data addressed to the wireless terminal 10 transmitted from the relay device 40, the application in the wireless terminal 10 Get information about.

The signal for transmitting information about the application in the wireless terminal 10 transmitted from the relay device 40 arranged in the mobile core network 51 may be converted in the mobile core network 51 and transferred to the wireless base station 21.

For example, when information about an application in the wireless terminal 10 is notified by being concatenated with an IP packet corresponding to data addressed to the wireless terminal 10, the wireless terminal 10 concatenated with the IP packet in the mobile network 51. Information about the application in the above may be transcribed by concatenation to the GTP packet corresponding to the IP packet and transferred to the radio base station 21. Alternatively, information about the application may be posted in the header area of the GTP packet and transferred to the radio base station 21. Further, in UDP or IP used in the lower layer of the GTP, the packet may be transcribed by the concatenation to the packet and transferred to the radio base station 21, or the packet may be transcribed and the radio base station 21 May be transferred to. Alternatively, a new interface for notifying the wireless base station 21 of the information on the mobile network may be installed, and the information may be transferred to the wireless base station 21 via the interface.

Information related to the application in the wireless terminal 10 is transmitted from the relay device 40 to the wireless base station 21 by means other than being concatenated with the IP packet corresponding to the data addressed to the wireless terminal 10 described in the present embodiment. Even when notified, the signal related to the information may be converted in the mobile core network and transferred to the radio base station 21 by various methods described above.

It should be noted that the above conversion can be performed at any node installed in the mobile core network 51. The conversion can also be carried out in the first and second embodiments.

The first to fifth embodiments described above may be implemented independently of each other, or may be implemented by appropriately combining a plurality of embodiments or parts (elements) of the embodiments. Good. For example, a combination of the radio base station of the first embodiment and the relay device 40 of the third or fourth embodiment, or the information acquisition unit 402 and / or the information notification unit of the relay device 40 of the third or fourth embodiment. The 403 may be mounted on the server device of the first or second embodiment, or the embodiments or parts (elements) may be combined as appropriate.

<Modification example>
In addition to the possible combinations of the above-described embodiments, the above-described embodiments may be implemented in the following modifications.

For example, the wireless terminal 10 provides information related to an application from the application layer to a lower RRC layer. The RRC layer processing unit of the wireless terminal 10 transmits information related to the application provided by the higher application layer (for example, information for calculating the amount of data that can be transmitted) to an RRC message (for example, RRC Connection Set Complete, RRC). It is included in the Connection Reconfiguration Calculation (Measurement Report) and transmitted. At this time, the information related to the application is transmitted in the same RRC message together with the information (for example, RSRP, RSRQ) for calculating the radio section throughput (for example, the amount of data that can be transmitted by the lapse of a predetermined time). It may be sent separately, or it may be sent separately.

The radio base station 20 (21) that has received the RRC message operates the communication control unit described above based on the information related to the application included in the RRC message and the information for calculating the radio section throughput. You may do so.

Further (or), the above-described embodiment may be applied to a configuration including MEC (Mobile Edge Computing) arranged in or near a radio base station. That is, in the communication system including the MEC server as the server device 30 (31) in the above-described embodiment, the wireless terminal 10, the wireless base station 20 (21), and the relay device 40, the operation of the above-described embodiment is performed. It may be. In this case, the relay device 40 is not an essential component. Alternatively, the relay device 40 may be virtually implemented in the MEC server.

Further (or), the above-described embodiment may be applied to a configuration including a data center (DC: Data Center) including a function of a radio base station and a function of a mobile core network. That is, the operation of the above-described embodiment may be performed in the communication system including the DC as the radio base station 21 in the above-described embodiment and the server device 31, the wireless terminal 10, and the relay device 40.

The DC may be a core DC or a distributed DC. Further, in this case, the relay device 40 is not an essential component. Alternatively, the relay device 40 may be virtually mounted on the DC.

An example in which the functions of the radio base station 20 (21), the server device 30 (31), and the relay device 40 described above are implemented by a program will be described. The radio base station 20 (21) includes a transceiver 20-1, an information processing device 20-2, and a communication interface 20-3, for example, as schematically shown in FIG. 13 (A). The transmitter 20-11 of the transceiver 20-1 power-amplifies the RF (Radio Frequency) signal obtained by frequency-converting (up-converting) the baseband signal to be transmitted into the carrier band and transmits the RF (Radio Frequency) signal from the antenna 20-13. The receiver 20-12 of the transceiver 20-1 amplifies the RF signal received by the antenna 20-13 with low noise, and frequency-converts (down-converts) the RF signal into a baseband signal. The information processing device 20-2 performs, for example, baseband signal processing, call processing, monitoring control, and the like. The information processing device 20-2 modulates the downlink packet data received from the mobile core network 51 side via the communication interface 20-3 into a baseband signal and transmits the downlink packet data to the transmitter 20-11. Further, the information processing device 20-2 demodulates the baseband signal received from the receiver 20-12 and transmits it to the mobile core network 51 via the communication interface 20-3. The information processing device 20-2 includes a central processing unit (CPU: Central Processing Unit) 20-21 and a storage device 20-22. The storage device 20-22 includes, for example, a semiconductor memory, a hard disk drive device (HDD), and the like. The storage device 20-22 stores a program executed by the CPU 20-21. The communication interface 20-3 communicates with the core network. The storage device 20-22 may be configured to include the buffer 202 of FIG. In the radio base station 20 (21), the CPU 20-21 executes the program stored in the storage device 20-22, so that the basic function unit 201 and the communication control unit 203 (213) of FIG. 2 (FIG. 9) are executed. It may be configured to realize a part or all of the functions of the change detection unit 204, the transmission amount estimation unit 205 (215), the inflow amount control unit 206, and the information notification unit 207.

The server device 30 (31) includes, for example, a communication interface 30-1 for communicating with the external network 52 and an information processing device 30-2, as schematically shown in FIG. 13 (B). The information processing device 30-2 includes a central processing unit (CPU) 30-21 and a storage device 30-22. The storage device 30-22 includes, for example, a semiconductor memory, a hard disk drive device (HDD), and the like. The storage device 30-22 stores a program executed by the CPU 30-21. In the server device 30 (31), when the CPU 30-21 executes the program stored in the storage device 30-22, the basic function unit 301 in FIG. 2 (FIG. 9) and the inflow amount control unit 302 in FIG. 2 It may be configured to realize some or all of the functions.

As shown in FIG. 13C, the relay device 40 includes an information processing device 40-1 and a communication interface 40-2. The information processing device 40-1 includes a central processing unit (CPU) 40-11, a storage device 40-12 (memory and hard disk drive device (HDD)), and the like. The storage device 40-12 stores a program executed by the CPU 40-11. The relay device 40 is one of the functions of the basic function unit 401, the information acquisition unit 402, the information notification unit 403, and the inflow amount control unit 404 by executing the program stored in the storage device 40-12 by the CPU 40-11. It may be configured to realize a part or all.

The disclosures of the above 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, it is possible to change or adjust the embodiments or examples based on the basic technical idea thereof. Further, various combinations or selections of various disclosure elements (including each element of each claim, each element of each embodiment, each element of each drawing, etc.) are possible within the scope of the claims of the present invention. .. 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.

The above embodiments are added as follows (but not limited to the following).

(Appendix 1)
If there is a change in the predetermined radio parameters related to the allocation of radio resources,
A transmission amount estimation step that calculates an estimated value of the data transmission amount to the wireless terminal from a buffer that temporarily stores data addressed to the wireless terminal transmitted from the source in consideration of the change of the wireless parameter.
Based on the estimated value of the data transmission amount from the buffer to the wireless terminal and the data storage amount to the wireless terminal stored in the buffer, the amount of data flowing into the buffer to the wireless terminal is determined. Inflow control step to control and
A data flow rate control method comprising.

(Appendix 2)
The radio parameters are
The state of the application in the wireless terminal and
The quality of the wireless line between the wireless base station and the wireless terminal,
The data flow rate control method according to Appendix 1, wherein the data flow rate is changed based on at least one of the above.

(Appendix 3)
The radio parameters are
The allocation priority of wireless resources in the wireless terminal and
An index (QoE (Quality of Experience) index) indicating the usage status of the application in the wireless terminal and
The wireless line quality of the wireless terminal and
The transmission power of the downlink data channel set in the wireless terminal and
The transmission mode (Transmission Mode) in the wireless terminal and
Antenna configuration in the wireless terminal and
The number of component carriers available to the wireless terminal and
Types of RAT (Radio Access Technology) that can be used by the wireless terminal, and
The radio resource allocation policy in the base station and
The data flow rate control method according to Appendix 1 or 2, wherein the data flow rate control method comprises at least one of.

(Appendix 4)
The delivery amount estimation step is
The step of calculating the expected value of the throughput of the radio section before and after the change of the radio parameter, and
A step of estimating the amount of data sent up to the lapse of a predetermined time using the expected value of the throughput, and
The data flow rate control method according to any one of Supplementary note 1 to 3, wherein the data flow rate control method comprises.

(Appendix 5)
The inflow control step
The data flow rate control method according to any one of Supplementary note 1 to 4, wherein the step of flowing the data inflow amount into the buffer is included.

(Appendix 6)
The inflow control step
The data flow rate control method according to any one of Supplementary Provisions 1 to 4, wherein when the value of the data inflow amount is 0 or negative, the data inflow to the buffer is suppressed.

(Appendix 7)
Further, an application information acquisition step for acquiring predetermined information about the application in the wireless terminal, and
A step of detecting a change in the radio parameter using the acquired predetermined information about the application, and
The data flow rate control method according to any one of Supplementary notes 1 to 6, wherein the data flow rate control method comprises.

(Appendix 8)
Further, it has an application information acquisition step of acquiring predetermined information about the application in the wireless terminal.
The delivery amount estimation step is
The data flow rate control method according to any one of Supplementary note 1 to 6, wherein the data transmission amount is estimated by using the acquired predetermined information about the application.

(Appendix 9)
A buffer that temporarily stores data sent from the source to the wireless terminal, and
A function to send the data stored in the buffer to the wireless terminal based on the allocation result of the wireless resource,
When there is a change in a predetermined radio parameter related to the allocation of the radio resource, a transmission amount estimation unit that calculates an estimated value of the data transmission amount from the buffer to the radio terminal in consideration of the change in the radio parameter. When,
An inflow amount control unit that calculates the amount of data inflow from the source to the buffer to the wireless terminal based on the estimated value of the data transmission amount and the amount of data stored in the buffer.
An information notification unit that notifies the source of the amount of data inflow, and
A radio base station apparatus comprising.

(Appendix 10)
The state of the application in the wireless terminal and
The quality of the wireless line between the wireless base station and the wireless terminal,
9. The radio base station apparatus according to Appendix 9, further comprising a change detection unit that detects a change in the radio parameter that is changed based on at least one of the radio parameters.

(Appendix 11)
The radio parameters are
The allocation priority of wireless resources in the wireless terminal and
An index (QoE (Quality of Experience) index) indicating the usage status of the application in the wireless terminal and
The wireless line quality of the wireless terminal and
The transmission power of the downlink data channel set in the wireless terminal and
The transmission mode (Transmission Mode) in the wireless terminal and
Antenna configuration in the wireless terminal and
The number of component carriers available to the wireless terminal and
Types of RAT (Radio Access Technology) that can be used by the wireless terminal, and
The radio resource allocation policy in the base station and
The radio base station apparatus according to Appendix 9 or 10, characterized in that it comprises at least one of.

(Appendix 12)
The transmission amount estimation unit
The expected value of the throughput of the radio section before and after the change of the radio parameter is calculated.
The radio base station apparatus according to any one of Supplementary note 9 to 11, wherein the data transmission amount is estimated after a lapse of a predetermined time using the expected value of the throughput.

(Appendix 13)
It has a function to acquire predetermined information about the application in the wireless terminal.
The change detection unit
The radio base station apparatus according to Appendix 10, wherein a change in the radio parameter is detected by using predetermined information about an application in the radio terminal.

(Appendix 14)
It has a function to acquire predetermined information about the application in the wireless terminal.
The transmission amount estimation unit
The wireless base station apparatus according to any one of Supplementary note 9 to 12, wherein the amount of data transmitted is estimated using predetermined information about an application in the wireless terminal.

(Appendix 15)
A function to receive data inflow information to wireless terminals calculated by a wireless base station via a communication network, and
A server device including an inflow amount control unit that controls the amount of data transmitted to the wireless terminal to the wireless base station based on the data inflow amount information.

(Appendix 16)
The inflow control unit
When the data inflow amount information is positive, the data addressed to the wireless terminal is additionally transmitted to the wireless base station by the amount of the data inflow amount.
The server device according to Appendix 15, wherein when the data inflow amount information is zero or negative, the data addressed to the wireless terminal is not transmitted to the wireless base station or the transmission is suppressed.

(Appendix 17)
A function that is connected between a wireless base station and a server device and relays data addressed to a wireless terminal transmitted from the server device to the wireless base station.
A receiving function for receiving data inflow information to a wireless terminal calculated by the wireless base station from the wireless base station via a communication network.
A data amount control unit that controls the amount of data transmitted to the wireless terminal to the wireless base station based on the data inflow amount information.
A relay device characterized by including.

(Appendix 18)
An information acquisition unit that acquires predetermined information about the application in the wireless terminal, and
An information notification unit that notifies the wireless base station of predetermined information about the application, and
The relay device according to Appendix 17, further comprising.

(Appendix 19)
The inflow control unit
When the data inflow amount information is positive, the data addressed to the wireless terminal is additionally transmitted to the wireless base station by the amount of the data inflow amount.
The relay device according to Appendix 17 or 18, wherein when the data inflow amount information is zero or negative, the data addressed to the wireless terminal is not transmitted to the wireless base station or the transmission is suppressed.

(Appendix 20)
A wireless base station including a buffer for temporarily storing data sent from a source to a wireless terminal and sending the data stored in the buffer to the wireless terminal based on the result of allocation of wireless resources is configured. To the computer
When there is a change in a predetermined radio parameter related to the allocation of the radio resource, a process of calculating an estimated value of the amount of data transmitted from the buffer to the radio terminal in consideration of the change of the radio parameter, and
A process of calculating the amount of data inflow from the source to the buffer to the wireless terminal based on the estimated value of the data transmission amount and the amount of data stored in the buffer.
The process of notifying the source of the data inflow amount and
A program that executes.

(Appendix 21)
The state of the application in the wireless terminal and
The quality of the wireless line between the wireless base station and the wireless terminal,
The program according to Appendix 20, which causes the computer to execute a process of detecting a change in the radio parameter that is changed based on at least one of the above.

(Appendix 22)
The radio parameters are
The allocation priority of wireless resources in the wireless terminal and
An index (QoE (Quality of Experience) index) indicating the usage status of the application in the wireless terminal and
The wireless line quality of the wireless terminal and
The transmission power of the downlink data channel set in the wireless terminal and
The transmission mode (Transmission Mode) in the wireless terminal and
Antenna configuration in the wireless terminal and
The number of component carriers available to the wireless terminal and
Types of RAT (Radio Access Technology) that can be used by the wireless terminal, and
The radio resource allocation policy in the base station and
The program according to Appendix 20 or 21, characterized in that it comprises at least one of.

(Appendix 23)
The processing unit that calculates the estimated value of the transmission amount is
The expected value of the throughput of the radio section before and after the change of the radio parameter is calculated.
The program according to any one of Supplementary note 20 to 22, which estimates the amount of data to be transmitted until a predetermined time has elapsed using the expected value of the throughput.

(Appendix 24)
Further provided with a process of acquiring predetermined information about the application in the wireless terminal,
The process of detecting the change is
The program according to Appendix 20, wherein changes in the wireless parameters are detected using predetermined information about the application in the wireless terminal.

(Appendix 25)
Further provided with a process of acquiring predetermined information about the application in the wireless terminal,
The process of estimating the transmission amount is
The program according to any one of Supplementary note 20 to 23, which estimates the amount of data transmitted by using predetermined information about an application in the wireless terminal.

(Appendix 26)
To the computers that make up the server device
Processing to receive data inflow information to wireless terminals calculated by a wireless base station via a communication network,
A process of controlling the amount of data transmitted to the wireless terminal to the wireless base station based on the data inflow amount information, and
A program that executes.

(Appendix 27)
When the data inflow amount information is positive, the data addressed to the wireless terminal is additionally transmitted to the wireless base station by the amount of the data inflow amount.
The program according to Appendix 26, wherein when the data inflow information is zero or negative, the computer is made to execute a process of not transmitting the data addressed to the wireless terminal to the wireless base station or suppressing the transmission.

(Appendix 28)
To a computer that is connected between a wireless base station and a server device and constitutes a relay device that relays data addressed to a wireless terminal transmitted from the server device to the wireless base station.
A process of receiving data inflow information to a wireless terminal calculated by the wireless base station from the wireless base station via a communication network.
A process of controlling the amount of data transmitted to the wireless terminal to the wireless base station based on the data inflow amount information, and
A program that executes.

(Appendix 29)
The process of acquiring predetermined information about the application in the wireless terminal, and
The program according to Appendix 28, which causes the computer to further execute a process of notifying the radio base station of predetermined information about the application.

(Appendix 30)
When the data inflow amount information is positive, the data addressed to the wireless terminal is additionally transmitted to the wireless base station by the amount of the data inflow amount.
The program according to Appendix 28 or 29, which causes the computer to further execute a process of not transmitting data addressed to the wireless terminal to the wireless base station or suppressing transmission when the data inflow information is zero or negative. ..

(Appendix 31)
With wireless terminals
Radio base station and
With the server device
With
The radio base station
A buffer that temporarily stores data destined for the wireless terminal transmitted from the server device, and
A function to send the data stored in the buffer to the wireless terminal based on the allocation result of the wireless resource,
When there is a change in a predetermined radio parameter related to the allocation of the radio resource, a transmission amount estimation unit that calculates an estimated value of the data transmission amount from the buffer to the radio terminal in consideration of the change in the radio parameter. When,
An inflow amount control unit that calculates the amount of data inflow from the server device to the buffer to the wireless terminal based on the estimated value of the data transmission amount and the amount of data stored in the buffer.
An information notification unit that notifies the server device of the amount of data inflow,
Including
The server device is
Receives the amount of data inflow transmitted from the wireless base station
A communication system including an inflow amount control unit that controls an amount of data transmitted to the wireless terminal to the wireless terminal based on the data inflow amount information.

(Appendix 32)
The radio base station
The state of the application in the wireless terminal and
The quality of the wireless line between the wireless base station and the wireless terminal,
31. The communication system according to Appendix 31, further comprising a change detection unit that detects a change in the radio parameter that is changed based on at least one of the above.

(Appendix 33)
It has a function to acquire predetermined information about the application in the wireless terminal.
The transmission amount estimation unit
The communication system according to Appendix 31 or 32, wherein the data transmission amount is estimated by using predetermined information about an application in the wireless terminal.

(Appendix 34)
With wireless terminals
Radio base station and
With the server device
A relay device connected between the radio base station and the server device,
With
The radio base station
A buffer that temporarily stores data destined for a wireless terminal transmitted from the server device via the relay device, and
A function to send the data stored in the buffer to the wireless terminal based on the allocation result of the wireless resource,
When there is a change in a predetermined radio parameter related to the allocation of the radio resource, a transmission amount estimation unit that calculates an estimated value of the data transmission amount from the buffer to the radio terminal in consideration of the change in the radio parameter. When,
An inflow amount control unit that calculates the amount of data inflow from the source to the buffer to the wireless terminal based on the estimated value of the data transmission amount and the amount of data stored in the buffer.
An information notification unit that notifies the relay device of the amount of data inflow, and
Including
The relay device
A receiving function for receiving data inflow information to the wireless terminal calculated by the wireless base station, and
When relaying the data addressed to the wireless terminal transmitted from the server device to the wireless base station, the amount of data for controlling the amount of data transmitted to the wireless base station to the wireless base station based on the data inflow amount information. A communication system including a control unit.

(Appendix 35)
The relay device
An information acquisition unit that acquires predetermined information about the application in the wireless terminal, and
The communication system according to Appendix 34, further comprising an information notification unit that notifies the radio base station of predetermined information about the application.

(Appendix 36)
The communication system according to Appendix 34 or 35, wherein the transmission amount estimation unit of the radio base station estimates the data transmission amount by using predetermined information about an application in the radio terminal.

(Appendix 37)
The communication system according to any one of Supplementary note 34 to 36, wherein the relay device is arranged in a core network to which the radio base station is connected or a packet data network connected to the core network.

(Appendix 38)
The radio base station
The state of the application in the wireless terminal and
The quality of the wireless line between the wireless base station and the wireless terminal,
The communication system according to any one of Supplementary note 34 to 37, further comprising a change detection unit that detects a change in the radio parameter that is changed based on at least one of the above.

(Appendix 39)
The radio parameters are
The allocation priority of wireless resources in the wireless terminal and
An index (QoE (Quality of Experience) index) indicating the usage status of the application in the wireless terminal and
The wireless line quality of the wireless terminal and
The transmission power of the downlink data channel set in the wireless terminal and
The transmission mode (Transmission Mode) in the wireless terminal and
Antenna configuration in the wireless terminal and
The number of component carriers available to the wireless terminal and
Types of RAT (Radio Access Technology) that can be used by the wireless terminal, and
The radio resource allocation policy in the base station and
33 or 38. The communication system according to Appendix 33 or 38, wherein the communication system comprises at least one of.

(Appendix 40)
In the radio base station
The transmission amount estimation unit
The expected value of the throughput of the radio section before and after the change of the radio parameter is calculated.
The communication system according to Appendix 31 or 34, wherein the data transmission amount is estimated after a lapse of a predetermined time using the expected value of the throughput.

1,1A, 1B communication system
10,910 wireless terminal
11 Mobile Access Network 20, 21, 920 Radio Base Station 20-1 Transceiver (TRX)
20-11 Transmitter (TX)
20-12 Receiver (RX)
20-13 Antenna 20-2 Information processing device 20-21 CPU
20-22 Storage device 20-3 Communication interface 30, 31, 930 Server device
30-1 Communication interface 30-2 Information processing device 30-21 CPU
30-22 Storage device 40 Relay device 40-1 Information processing device 40-2 Communication interface 40-11 CPU
40-12 Storage device 50, 940 Communication line network 51 Mobile core network 52 External network
201 Basic functions
202, 921 buffer
203, 213 Communication control unit
204 Change detector
205, 215 Transmission amount estimation unit
206 Inflow control unit
207 Information notification section
301 Basic Function Department
302 Inflow control unit
401 Basic functions
402 Information acquisition department
403 Information Notification Department
404 Inflow control unit 931 Storage device 950 Wireless interface 960 P-GW

Claims (10)

As an index for allocating wireless resources to a wireless terminal, an index obtained by weighting and adding a predetermined index related to a plurality of wireless parameters is used.
When at least one of the radio parameters is changed, the estimated value of the amount of data transmitted to the radio terminal from the buffer that temporarily stores the data destined for the radio terminal transmitted from the source is used as the allocation index of the radio resource. A transmission amount estimation step calculated based on the degree of change before and after the wireless parameter change and the data transmission amount from the buffer to the wireless terminal before the wireless parameter is changed .
Wherein the estimate of the data transmission amount from the buffer to the radio terminal, in addition to the amount of data stored in the addressed wireless terminal stored in the buffer, the target value of the amount of data accumulated in the addressed wireless terminal in said buffer , Inflow control for controlling the amount of data flowing into the buffer to the wireless terminal based on at least one of the amount of data transmitted from the source to the wireless terminal and flowing into the buffer per unit time. A data flow control method comprising: steps. As an index for allocating wireless resources to a wireless terminal, an index obtained by weighting and adding a predetermined index related to a plurality of wireless parameters is used.
When at least one of the radio parameters is changed, the degree of change of the radio resource allocation index before and after the radio parameter change and the radio section between the radio terminal and the base station before the radio parameter is changed. Calculate the expected value of the throughput of the radio section from the throughput of
Based on the expected value of the throughput of the wireless section, the amount of data transmitted to the wireless terminal from the buffer that temporarily stores the data destined for the wireless terminal transmitted from the source is obtained.
In addition to the estimated value of the data transmission amount from the buffer to the wireless terminal and the data storage amount to the wireless terminal stored in the buffer, the target value of the data storage amount to the wireless terminal in the buffer. Control the amount of data flowing into the buffer to the wireless terminal based on at least one of the amount of data transmitted from the source to the wireless terminal and flowing into the buffer per unit time. A characteristic data flow control method. Obtaining the required radio resources necessary to realize the expected value of throughput in the radio section,
Calculate the wireless resources that can be allocated to the second wireless terminal,
The expected value of the throughput of the second radio section after changing the radio parameter for the second radio terminal was obtained.
From the expected value of the throughput of the second wireless section, the amount of data transmitted to the second wireless terminal is obtained.
In addition to the estimated value of the data transmission amount from the buffer to the second radio terminal and the data storage amount to the second radio terminal stored in the buffer, the second radio in the buffer. The second item in the buffer is based on a target value of the amount of data stored in the terminal and at least one of the amount of data per unit time flowing into the buffer from the source to the second wireless terminal. The data flow control method according to claim 2, wherein the amount of data inflow to the wireless terminal is controlled. The radio resource allocation index is
The elapsed time from the transmission of the packet from the source to the arrival at the wireless terminal,
Whether the packet is resent or not
Communication quality of the wireless terminal with the wireless resource
The data flow rate control method according to any one of claims 1 to 3, which comprises an index obtained by weighting and adding at least two of the three radio parameters. A buffer that temporarily stores data sent from the source to the wireless terminal, and
A function to send the data stored in the buffer to the wireless terminal based on the allocation result of the wireless resource,
As an index for allocating wireless resources to a wireless terminal, an index obtained by weighting and adding predetermined indexes related to a plurality of wireless parameters is used, and when at least one of the wireless parameters is changed, the wireless terminal transmitted from the source is addressed. The estimated value of the amount of data transmitted from the buffer that temporarily stores the data to the wireless terminal is the degree of change of the wireless resource allocation index before and after the wireless parameter change, and before the wireless parameter is changed. A transmission amount estimation unit calculated based on the data transmission amount from the buffer to the wireless terminal , and
Wherein the estimate of the data transmission amount from the buffer to the radio terminal, in addition to the amount of data stored in the addressed wireless terminal stored in the buffer, the target value of the amount of data accumulated in the addressed wireless terminal in said buffer , The amount of data inflow from the source to the buffer to the wireless terminal is calculated based on at least one of the amount of data transmitted from the source to the wireless terminal and flowing into the buffer per unit time. Inflow control unit and
An information notification unit that notifies the source of the amount of data inflow, and
A radio base station apparatus comprising. As an index for allocating wireless resources to a wireless terminal, an index obtained by weighting and adding a predetermined index related to a plurality of wireless parameters is used.
When at least one of the radio parameters is changed, the degree of change of the radio resource allocation index before and after the radio parameter change and the radio section between the radio terminal and the base station before the radio parameter is changed. Calculate the expected value of the throughput of the radio section from the throughput of
Based on the expected value of the throughput of the wireless section, the data transmission amount to the wireless terminal is obtained from the buffer that temporarily stores the data addressed to the wireless terminal transmitted from the source, and the transmission amount estimation unit and the transmission amount estimation unit.
In addition to the estimated value of the data transmission amount from the buffer to the wireless terminal and the data storage amount to the wireless terminal stored in the buffer, the target value of the data storage amount to the wireless terminal in the buffer. , Inflow control for calculating the amount of data flowing into the buffer to the wireless terminal based on at least one of the amount of data transmitted from the source to the wireless terminal and flowing into the buffer per unit time. Department and
An information notification unit that notifies the source of the amount of data inflow addressed to the wireless terminal, and
A radio base station apparatus comprising. The transmission amount estimation unit
Obtaining the required radio resources necessary to realize the expected value of throughput in the radio section,
Calculate the wireless resources that can be allocated to the second wireless terminal,
The expected value of the throughput of the second radio section after changing the radio parameter for the second radio terminal was obtained.
From the expected value of the throughput of the second wireless section, the amount of data transmitted to the second wireless terminal is obtained.
The inflow control unit
In addition to the estimated value of the data transmission amount from the buffer to the second radio terminal and the data storage amount to the second radio terminal stored in the buffer, the second radio in the buffer. The second item in the buffer is based on a target value of the amount of data stored in the terminal and at least one of the amount of data per unit time flowing into the buffer from the source to the second wireless terminal. Calculate the amount of data inflow to the wireless terminal,
The wireless base station device according to claim 6, wherein the information notification unit notifies the transmission source of the amount of data inflow addressed to the second wireless terminal. The elapsed time from the transmission of the packet from the source to the arrival at the wireless terminal, based on the wireless resource allocation index,
Whether the packet is resent or not
Communication quality of the wireless terminal with the wireless resource
The radio base station apparatus according to any one of claims 5 to 7, which comprises an index obtained by weighting and adding at least two of the three radio parameters. Wherein in any one of claims 5 to 8 connected between the radio base station apparatus and the transmission source server device, from the server device of the addressed wireless terminal which is transmitted to the radio base station apparatus A function to relay data and
A receiving function of the data flow rate information of the addressed wireless terminal calculated in the radio base station apparatus receives, via the communication network from the radio base station apparatus,
A data amount control unit that controls the amount of data transmitted to the wireless terminal to be transmitted to the wireless base station device based on the data inflow amount information.
A relay device characterized by including. A wireless base station including a buffer for temporarily storing data sent from a source to a wireless terminal and sending the data stored in the buffer to the wireless terminal based on the result of allocation of wireless resources is configured. To the computer
As an index for allocating the radio resources to the radio terminal, an index obtained by weighting and adding a predetermined index related to a plurality of radio parameters is used, and when at least one of the radio parameters is changed, the radio terminal transmitted from the source. The estimated value of the amount of data sent from the buffer that temporarily stores the destination data to the wireless terminal is changed according to the degree of change of the wireless resource allocation index before and after the wireless parameter change and the wireless parameter. Processing calculated based on the amount of data transmitted from the buffer to the previous wireless terminal , and
In addition to the estimated value of the data transmission amount from the buffer to the wireless terminal and the data storage amount to the wireless terminal stored in the buffer, the target value of the data storage amount to the wireless terminal in the buffer. A process of calculating the amount of data flowing into the buffer to the wireless terminal based on at least one of the amount of data transmitted from the source to the wireless terminal and flowing into the buffer per unit time .
The process of notifying the source of the data inflow amount and
A program that executes.

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