WO2014073131A1 - Wireless-resource setting method, system, base station, and non-transitory computer-readable medium - Google Patents

Abstract

Related technologies have had the problem that terminals connected to a cell that has implemented a wireless-resource allocation restriction suffer decreased throughput fairness. This wireless-resource setting method is executed for a first communication area managed by a first wireless base station and a second communication area that is managed by a second wireless base station and encompasses part of or is adjacent to the first communication area. A resource utilization percentage for the first communication area is compared to a prescribed value, and the relative loads on the first wireless base station and the second wireless base station are compared. If the resource utilization percentage for the first communication area is greater than or equal to the prescribed value and the load on the first wireless base station is determined to be high relative to the load on the second wireless base station on the basis of a predetermined criterion, wireless resources for the second communication area are controlled.

Description

Radio resource setting method, system, base station, and non-transitory computer-readable medium

The present invention relates to a radio resource setting method, system, base station, and non-transitory computer-readable medium, and more particularly, to an assigned radio resource setting method for suppressing interference with neighboring cells.

For example, a wireless communication system such as LTE (Long Termination Evolution) standardized in 3GPP (Third Generation Partnership Project) has a plurality of base stations, and each base station has a communication area allocated to the base station. It communicates with a terminal (mobile station) located within (hereinafter referred to as a cell). In addition, a cell can be divided into a plurality of parts by imparting directivity to the antenna, and this divided area is called a sector cell. In the following description, the cell includes not only a normal cell but also a sector cell.

LTE normally uses the same communication band between adjacent cells. Therefore, a terminal located at the boundary between cells (hereinafter referred to as an edge terminal) receives strong interference from adjacent cells regardless of uplink or downlink. In order to deal with such a problem, a priority band capable of preferentially communicating with the terminal of the own cell is set. Each cell uses an interference management technique called ICC (Inter-Cell Interference-Coordination) that suppresses interference between adjacent cells by limiting radio resources allocated to terminals for the priority bands of adjacent cells. . As the limitation of the radio resource, it is conceivable to exclude the notified priority band from the allocation target or to reduce the transmission power.

As a priority band setting method, a technique called FFR (FractionalracFrequency Reuse) that performs partial frequency repetition so that priority bands do not overlap between cells is known (Non-Patent Document 1). As a priority band notification method, LTE is standardized for LOAD INFORMATION. For example, LTE downlink can use RNTP (Relative Narrowband TX Power) that is transmission power information for each resource block from the base station, and uplink can use HII (High Interference Indication) (non-patent). Reference 2).

Furthermore, as a countermeasure against the increase in traffic volume in recent years, a heterogeneous network in which cells of various sizes are mixed by introducing a base station (small cell base station) with low transmission power in addition to a conventional macro base station ( Heterogeneous Network has attracted attention, but the cell boundary area expands as the number of cells increases, so inter-cell interference is regarded as a problem. In 3GPP Release 10, eICIC (enhanced ICIC) was studied as interference management technology, and ABS (Almost Blank Subframe) was standardized (Non-Patent Document 3).

EICIC is also called time domain ICIC. If it is a downlink, the base station which set ABS will stop transmission of a physical downlink control channel (PDCCH: (Physical) Downlink (Control) Channel) and a physical downlink shared channel (PDSCH: (Physical) Downlink | Shared | Channel). As a result, the desired signal power-to-interference and noise power ratio (SINR: Signal-to-Interference-and-Noise-power-Ratio) of terminals in adjacent cells is greatly improved, and an increase in throughput of the corresponding terminals can be expected.

Incidentally, as a priority band notification condition in ICIC, Related Technique 1 (Non-Patent Document 4) proposes “when there are a predetermined number or more of terminals whose communication path quality is lower than the required quality”. With Related Technology 1, when a terminal is at the end of a cell, a priority band can be notified to an adjacent cell. However, in the related technique 1, when the number of terminals of the cell to which the priority band is notified is large, the 5% value of the cumulative distribution of throughput of all terminals in the wireless communication system deteriorates, and the fairness of the throughput between terminals is lost. There was a problem. This is because a cell having a large number of terminals limits the radio resources allocated to the terminals even though the communication band allocated per terminal is small and the throughput of each terminal is originally low.

In Patent Document 1, for a radio resource that can be used as a PDSCH, a resource division ratio that is a ratio of a macro cell unavailable PDSCH resource and a macro cell usable PDSCH resource is determined. A method of allocating radio resources to radio terminals connected to a macro cell base station from among macro cell usable PDSCH resources determined according to the determined resource division ratio is provided.

JP 2012-129646 A

As described above, the related technology has a problem that the fairness of the throughput of a terminal connected to a cell in which the allocation of radio resources is restricted is lost.

The present invention has been made to solve the above-described problem, and a radio resource setting method, system, base station, and non-temporary method that improve the fairness related to the throughput of a plurality of terminals accommodated in each of a plurality of communication areas. Computer readable media can be provided.

A radio resource setting method according to an aspect includes a first communication area managed by a first radio base station and a second radio base station that is adjacent to or includes a part of the first communication area. For the second communication area, the resource usage rate of the first communication area is compared with a predetermined value, and the load of the first radio base station and the load of the second radio base station are calculated. The relative load of the first radio base station and the second radio base station is compared, the resource usage rate of the first communication area is equal to or greater than the predetermined value, and the first radio base station When it is determined that the load is relatively large based on a predetermined criterion relative to the load of the second radio base station, the radio resources of the second communication area are controlled.

A wireless communication system according to an aspect includes a first wireless base station that manages a first communication area, and a second communication area that manages a second communication area that is adjacent to or part of the first communication area. A radio base station is provided. Then, a means for comparing the resource usage rate of the first communication area with a predetermined value, a load of the first radio base station and a load of the second radio base station are calculated, and the first radio Means for comparing the relative loads of the base station and the second radio base station, and the resource usage rate of the first communication area is equal to or greater than the predetermined value, and the load of the first radio base station Means for controlling the radio resources of the second communication area when it is determined that is relatively large based on a predetermined criterion relative to the load of the second radio base station. Yes.

A non-transitory computer-readable medium that causes a computer to execute the radio resource setting method according to one aspect includes a first communication area managed by a first radio base station, and adjacent to or a part of the first communication area For the second communication area managed by the second radio base station that includes the above, the resource usage rate of the first communication area is compared with a predetermined value, and the load of the first radio base station and the second A load of the radio base station is calculated, a relative load of the first radio base station and the second radio base station is compared, and a resource usage rate of the first communication area is equal to or greater than the predetermined value And when it is determined that the load of the first radio base station is relatively large based on a predetermined criterion compared to the load of the second radio base station, Decision to control radio resources in the communication area To execute a process for the computer.

The radio base station according to one aspect manages a second communication area that is adjacent to or part of the first communication area managed by another radio base station. The resource usage rate of the first communication area is equal to or greater than the predetermined value, and the load of the first radio base station is a predetermined criterion compared to the load of the second radio base station When it is determined that the radio resource is relatively large based on the radio resources, the radio resources of the second communication area are controlled.

The radio base station according to one aspect manages the first communication area. A resource usage rate of the first communication area is equal to or greater than the predetermined value, and a load of the radio base station is a second communication area that is adjacent to or partially includes the first communication area. When it is determined that the load is relatively large based on a predetermined criterion as compared with the load of another radio base station to be managed, the determination result for controlling the radio resource of the second communication area Notify the base station.

According to the present invention, it is possible to provide a radio resource setting method, system, base station, and non-transitory computer-readable medium that improve the fairness related to the throughput of a plurality of terminals accommodated in each of a plurality of communication areas.

It is a figure showing the structure of the radio | wireless communications system in 1st Embodiment. It is a figure showing the structure of the pico base station and macro base station in 1st Embodiment. It is a figure showing the structure of the terminal in 1st Embodiment. It is a figure which shows the setting method of the priority band of the pico base station in 1st Embodiment. It is a figure which shows the implementation determination method of the radio | wireless resource allocation limitation of the macro base station in 1st Embodiment. It is a figure showing the structure of the pico base station and macro base station in 2nd Embodiment. It is a figure which shows the setting method of the priority band of the pico base station in 2nd Embodiment. It is a figure which shows the implementation determination method of the radio | wireless resource allocation restriction | limiting of the macro base station in 2nd Embodiment. It is a figure which shows the implementation determination method of the radio | wireless resource allocation limitation of the macro base station in 2nd Embodiment. It is a figure showing the structure of the pico base station and macro base station in 3rd Embodiment. It is a figure which shows the determination method of the edge terminal in 3rd Embodiment. It is a figure which shows the setting method of the priority band of the pico base station in 3rd Embodiment. It is a figure which shows the subject in related technology. It is a figure which shows the subject in related technology.

First, the prior application (Japanese Patent Application No. 2011-36659) filed earlier by the applicant will be described with a focus on differences from the present invention. In the prior application, it is defined using the PRB (Physical Resource Block) usage rate, the number of Active UEs, etc. (Non-Patent Document 5), which are units of radio resources used in communication in the cell to which the priority band is notified. We proposed a method to limit the allocation of radio resources to terminals only when the load is less than the threshold. As a result, a cell with a large number of terminals and originally low throughput of terminals can avoid the limitation of allocated radio resources.

Here, since the PRB usage rate, the number of Active UEs, and the like are past actual values, in the embodiment of the prior application, there is a problem that only the throughput of the terminal connected to the cell in which the radio resource allocation is restricted is deteriorated. was there.
In the embodiment of the prior application, when the number of edge terminals is equal to or greater than the threshold value, the priority band is notified to the neighboring cell. Only when the number of terminals is smaller than that of the notification source cell, the notification destination cell limits the allocation of radio resources. As illustrated in FIG. 13, it is assumed that the wireless communication system includes a base station A that manages the pico cell A and a base station B that manages the macro cell B, and has three thresholds. Base station A is a base station with low transmission power. In addition, there are five terminals in the pico cell A, and four of them (A2 to A5) are edge terminals located at the cell boundary. Macro cell B has three terminals (B1 to B3), all of which are center terminals.

According to the embodiment of the prior application, since the number of edge terminals of pico cell A is four, which is larger than the threshold value, pico cell A notifies macro cell B of the priority band. Since the number of terminals of the macro cell B that is the notification destination is three, which is less than the number of terminals of the pico cell A that is the notification source, the macro cell B has a radio resource such as reducing the transmission power to the notified priority band. Allocate quotas for a certain period of time.
However, as shown in FIG. 14, the time during which the terminal of the pico cell A communicates may be shorter than the time during which the macro cell B restricts the allocation of radio resources. At this time, the throughput of the terminal of the pico cell A is not improved due to the large number of terminals, and the throughput of the terminal of the macro cell B is deteriorated due to radio resource allocation limitation.
The present invention has been conceived in consideration of solving such problems.

[First embodiment]
In the first embodiment, the pico cell determines whether the resource usage rate estimated from its own buffer size and transmission rate is equal to or greater than a threshold value, and notifies the determination result to the macro cell using RNTP. When the macro cell receives a notification that RNTP is 1, it determines whether the relative load of the pico cell is equal to or greater than a threshold value, and if so, restricts allocation of radio resources (suppresses transmission power).
Next, the present embodiment will be described in detail with reference to the drawings.

[Description of configuration]
FIG. 1 shows the configuration of radio communication system 10 according to the first embodiment.
The radio communication system 10 applies the present invention to the LTE downlink.
The wireless communication system 10 includes pico base stations 100a, 100b,..., Macro base stations 200a, 200b,..., And a plurality of terminals 300-P1-1 (300e), 300-P1-2 (300f),. -M1-1 (300a), 300-M1-2 (300b),. M is an acronym for Macro, and P is an acronym for Pico. Here, terminal 300-P1-X indicates that it is connected to pico base station 100a. In addition, the terminal 300-M1-Y indicates that it is connected to the macro base station 200a. X and Y are arbitrary indexes for identifying a terminal in each base station.

In the following explanation, when the matters common to each pico base station and each macro base station are described, they are described as “pico base station 100 is” and “macro base station 200 is”, respectively. Similarly, for the terminals, when describing items common to each terminal connected to the pico base station and each terminal connected to the macro base station, “terminal 300-P is”, “terminal” "300-M is ..." In addition, when a common item is described regardless of the base station to which it is connected, it is described as “terminal 300 is”.

The pico base stations 100a, 100b, ... and the macro base stations 200a, 200b, ... can communicate with each other via the communication line NW. Each pico base station 100 and each macro base station 200 can manage a plurality of communication areas (cells). In this embodiment, each pico base station 100 and each macro base station 200 manage one communication area.

The pico base station 100 is a low transmission power base station, and has a smaller communication area than the macro base station 200. The communication area of each pico base station 100 includes at least a part of the communication area in the communication area of each macro base station 200.
Each pico base station 100 performs wireless communication with a terminal 300-P existing in a communication area managed by the base station 100. Each pico base station 100 can perform wireless communication simultaneously with each of a plurality of terminals 300-P (300e to 300h).

Each macro base station 200 wirelessly communicates with terminals 300-M (300a to 300d) existing in the communication area excluding the communication area managed by the pico base station 100 from the communication area managed by the base station 200. Communicate. Each macro base station 200 can perform wireless communication simultaneously with each of the plurality of terminals 300-M (300a to 300d).

Each pico base station 100 and each macro base station 200 includes an information processing device (not shown). The information processing apparatus includes a central processing unit (CPU) (not shown) and a storage device (memory and hard disk drive (HDD)). Each pico base station 100 and each macro base station 200 are configured to realize functions to be described later when a CPU executes a program stored in a storage device.

Each terminal 300 is a mobile phone terminal. Each terminal 300 may be a personal computer, a PHS (Personal Handyphone System) terminal, a PDA (Personal Data Assistant, Personal Digital Assistant), a smartphone, a car navigation terminal, a game terminal, or the like.

Each terminal 300 includes a CPU, a storage device (memory), an input device (key buttons and a microphone), and an output device (display and speaker). Each terminal 300 is configured to realize functions to be described later when the CPU executes a program stored in the storage device.

FIG. 2 is a block diagram showing the functions of each pico base station 100 and each macro base station 200 in the wireless communication system 10 configured as described above. The pico base station will be described as a pico base station 100a, and the macro base station will be described as a macro base station 200a. Although not shown in the figure, the functions of the pico base station 100b,... Are the same as the functions of the pico base station 100a. Similarly, the functions of the macro base station 200b,... Are the same as the functions of the macro base station 200a.

The pico base station 100a includes a base station operation unit 101, a reference signal generation unit 102, a load measurement unit 103, a transmission buffer 104, a scheduler 105, and a priority band setting unit 106.

The base station operation unit 101 has a function of transmitting and receiving a radio signal between each terminal 300-P1 connected to the pico base station 100a. Also, the base station operation unit 101 notifies each terminal 300-P1 (300e to 300d) of scheduling information such as an allocated band used for transmission / reception of radio signals, MCS (Modulation and Coding Scheme) Index, and transmission power setting information. It has a function. Furthermore, the base station operation unit 101 has a peripheral base station list in which information used for identifying the macro base station 200a and other peripheral macro base stations is described, and the peripheral base station via the communication line NW. It also has a function to communicate with a station. Since these functions of the base station operation unit 101 are well-known functions in a general wireless communication system, description thereof is omitted.

The reference signal generation unit 102 has a function of generating a reference signal used by the terminal 300 to measure the communication channel quality with the pico base station 100a. The generated signal is transmitted to each terminal 300 via the base station operation unit 101.

The load measuring unit 103 measures the load of the pico base station 100a at every predetermined period, and notifies the information of the measured load to the surrounding base stations including at least the macro base station 200a via the base station operation unit 101. It has the function to do. In this embodiment, the PRB usage rate is used as the load. The measured load is used by the priority band setting unit 106 via the base station operation unit 101.
The transmission buffer 104 has a function of accumulating transmission data addressed to each terminal 300-P (300e to 300d) arriving via the communication line NW and its information.

The scheduler 105 stores the transmission data size addressed to each terminal 300-P (300e to 300d) stored in the transmission buffer 104, the CQI (Channel Quality な ど Indicator) reported from each terminal 300-P (300e to 300d), and the like. The transmission power, the frequency band, and the MCS index assigned to each terminal 300-P are determined based on the CSI (Channel State Information) information, and data is transmitted via the base station operation unit 101.

The priority band setting unit 106 has a function of estimating the resource usage rate of the pico base station 100a from the size (hereinafter referred to as buffer size) of transmission data staying in the transmission buffer 104 and the load. Note that the function of estimating the resource usage rate of the pico base station 100a may be realized by another processing method. For example, it can be realized by the method described in the following paragraph 0066, the method described in paragraph 0085, or the like.
Further, using the estimated resource usage rate of the pico base station 100a, it is determined whether or not the priority band of the pico base station 100a is set, and the determination result is displayed as a neighboring base station list managed by the base station operation unit 101. With reference, it has the function to notify at least the macro base station 200a. In this embodiment, the priority band is a system band, and RNTP (Relative Narrowband TX Power), which is transmission power information for each resource block from the base station, is used for notification of the determination result. In RNTP, an RB (Resource Block) set to the priority band is set to 1, and an RB not set to the priority band is set to 0. RB represents a frequency block, which is a radio band allocation unit. In the present embodiment, when the priority band setting unit 106 sets the priority band of the pico base station 100a, the RNTP of all RBs is set to 1 and notified, and when not set, the RNTP of all RBs is set to 0. Set and notify.

The macro base station 200a includes a base station operation unit 201, a reference signal generation unit 202, a load measurement unit 203, a transmission buffer 204, an assigned radio resource setting unit 205, and a scheduler 206.
The base station operation unit 201 has a function of transmitting and receiving a radio signal between each of the terminals 300-M1 (300a to 300d) connected to the macro base station 200a. Also, the base station operation unit 201 determines scheduling information such as an allocated band and MCS index used for transmission / reception of radio signals, and transmission power setting information for each terminal 300-M1 (300a to 300d), and each terminal 300-M1. It also has a function of notifying (300a to 300d). Further, the base station operation unit 201 describes information used to identify the pico base station 100a, the neighboring macro base stations, and the pico base stations installed in the communication area of each neighboring macro base station. And a function of performing communication with the peripheral base station via the communication line NW. Since these functions are well-known functions in a general wireless communication system, description thereof is omitted.
Since the reference signal generation unit 202 has the same function as the reference signal generation unit 102 of the pico base station 100a, description thereof is omitted.

The load measurement unit 203 measures the load of the macro base station 200a every predetermined period, and notifies the information of the measured load to the neighboring base stations including at least the pico base station 100a via the base station operation unit 201. It has the function to do. The measured load is used by the allocated radio resource setting unit 204 via the base station operation unit 201.
Since the transmission buffer 204 has the same function as the transmission buffer 104 of the pico base station 100a, the description thereof is omitted.

The allocated radio resource setting unit 205 uses the RNTP and the load information notified from the pico base station 100a and the load of the macro base station 200a measured by the load measuring unit 103, so that the macro base station 200a uses the terminal 300-M1 ( 300a, 300b) has a function of determining whether or not to restrict the allocation of radio resources. In the present embodiment, when the allocated radio resource setting unit 205 determines to limit the allocation of radio resources to the terminal 300-M1 (300a, 300b), the terminal 300-M1 (300a, 300b) The assignable band is set as the system band, and the transmission power of the PDSCH, which is the data channel, is set to a transmission power that is smaller by a predetermined value than the preset reference transmission power.

Further, when the allocation restriction execution determination unit 205 determines not to limit wireless resource allocation to the terminal 300-M1 (300a, 300b), for each terminal 300-M1 (300a, 300b), The band that can be allocated is set as the system band, and the transmission power is set at a preset reference transmission power.
Since the scheduler 206 has the same function as the scheduler 105 of the pico base station 100a, the description thereof is omitted.

FIG. 3 is a block diagram showing functions of the terminal 300-P1-1 (300e) in the wireless communication system 10. Although not shown in the figure, the functions of the terminal 300-P1-1 (300e) are as follows: terminal 300-P1-2 (300f),..., Terminal 300-P2-1 (300g), terminal 300-P2 -2 (300h),..., Terminal 300-M1-1 (300a), terminal 300-M1-2 (300b),...
The functions of the terminal 300-P1-1 (300e) include a terminal operation unit 301 and a channel quality measurement unit 302.

The terminal operation unit 301 is a well-known function in a general wireless communication system, such as a function of transmitting / receiving a radio signal to / from the pico base station 100a connected to the terminal 300 (a communication link is established). Detailed description will be omitted.
The channel quality measuring unit 302 has a function of measuring channel quality with respect to the reference signal and transmitting information on the measured channel quality to the pico base station 100a. In this embodiment, the channel quality is a CQI calculated from the RSRP and the SINR for the reference signal.

[Description of operation]
Next, the operation of the above-described wireless communication system 10 will be described with reference to FIGS.
FIG. 4 shows an operation procedure in which the priority band setting unit 106 of the pico base station 100a determines whether or not to set the priority band of the pico base station 100a. The priority band setting unit 106 performs the operation illustrated in FIG. 4 for each period in which the load measurement unit 103 notifies the macro base station 200a of the PRB usage rate.

First, the transmission bit number TB (Transmitted Bits) per RB of the pico base station 100a is calculated according to the following equation (1) (S101).
TB = (BS_past + ΔS-BS_present) / (U_pico × N_PRB × T) (1)

For the calculation, the PRB usage rate U_pico of the pico base station 100a measured by the load measuring unit 103, the buffer size BS_present remaining in the transmission buffer 104 at the current time, and the transmission buffer at a time T a predetermined time before the current time The buffer size BS_past staying at 104 and the data size ΔS arriving at the transmission buffer 104 between that time and the present are used.

In the right side of Equation (1), the numerator represents the total data size that has been transmitted by the pico base station 100a at the predetermined time T, and the denominator is the total number of PRBs used for data transmission by the pico base station 100a at the predetermined time T. Represents. N_PRB is the number of PRBs that can be allocated per time frame (Subframe), which is a time unit of data transmission, and T is the PRB usage rate notification period.

Next, as a resource usage rate of the pico base station 200a, an estimated value (hereinafter referred to as an estimated PRB usage rate) U_pico_est of a PRB usage rate after a predetermined time T has elapsed from the current time of the pico base station 100a Calculate according to 2) (S102).
U_pico_est = MIN [1.0, (BS_present / TB) / (N_PRB × T)] (2)
According to the formula (2), an estimate is a ratio of the total number of PRBs that can be used until the predetermined time T elapses from the current time to the total number of PRBs necessary for completing transmission of data staying in the transmission buffer. PRB usage rate can be estimated. As described above, the process of comparing the resource usage rate in the communication area of the pico base station with a predetermined value is executed by the processes shown in S101 and S102.

Next, it is determined whether or not the estimated PRB usage rate U_pico_est of the pico base station 100a is equal to or greater than a threshold value U_thr (S103).
If the estimated PRB usage rate U_pico_est of the pico base station 100a is equal to or greater than the threshold value U_thr (S103, Yes), the pico base station 100a and the terminals 300-P (300e to 300h) until the predetermined time T elapses from the current time. ), The priority band setting unit 106 sets the RNTP of all RBs to 1, and notifies the macro base station 200a (S104). Thereafter, the process of FIG. 4 is terminated.

If the estimated PRB usage rate U_pico_est of the pico base station 100a is less than the threshold value U_thr (S103, No), the pico base station 100a and the terminal 300-P (300e) until the predetermined time T elapses from the current time. ˜300h), the priority band setting unit 106 sets the RNTP of all RBs to 0 and notifies the macro base station 200a (S105). Thereafter, the process of FIG. 4 is terminated.

FIG. 5 shows an operation procedure in which the allocated radio resource setting unit 204 of the macro base station 200a sets radio resources that can be allocated to each terminal 300-M1 connected to the macro base station 200a. The allocated radio resource setting unit 204 executes the operation illustrated in FIG. 5 every time it receives an RNTP from the pico base station 100a.
First, it is determined whether or not RNTP notified from the pico base station 100a to the macro base station 200a is 1 (S201).

When the RNTP notified from the pico base station 100a to the macro base station 200a is 1 (S201, Yes), the relative load ΔU_pico of the pico base station 100a is calculated according to Equation (3) (S202).
ΔU_pico = U_pico-U_macro (3)

U_pico represents the PRB usage rate of the latest pico base station 100a received from the pico base station 100a, and U_macro represents the PRB usage rate of the macro base station 200a measured by the load measurement unit 203. As the relative load ΔU_pico of the pico base station 100a is larger, the pico base station 100a has a larger number of terminals and a lower throughput of the terminals than the macro base station 100a.

Next, it is determined whether or not the relative load ΔU_pico of the pico base station 100a is greater than or equal to the threshold value ΔU_thr (S203). As described above, the process shown in S201 to S203 calculates the load of the pico base station and the load of the macro base station, and executes the process of comparing the relative loads of the pico base station and the macro base station.

When the relative load ΔU_pico of the pico base station 100a is equal to or greater than the threshold value ΔU_thr (S203, Yes), it is determined that the throughput of the terminal of the pico base station 100a is sufficiently low compared to the throughput of the terminal of the macro base station 200a. It is determined whether the value obtained by subtracting a constant value P_offset (> 0 dB) from the PDSCH transmission power P_pdsch of the base station 200a and the reference power P_rs is equal (S204). The reference power P_rs is transmission power when radio resources that can be used in the macro base station 200a are not limited.

If the two are equal (S202, Yes), the macro base station 200a determines that the restriction of radio resource allocation has already been implemented for the terminal 300-M1, and ends the processing of FIG. On the other hand, when the two are not equal (S204, No), the macro base station 200a determines that radio terminal allocation is not restricted for the terminal 300-M1, and the transmission power P_pdsch is changed from P_rs to P_offset (> 0 dB). ) Update to a smaller value (S205). In the processing shown in S204 and S205, since the relative load between the pico base station and the macro base station is high, processing for controlling transmission power is executed. The setting information of the transmission power P_pdsch is notified to each terminal 300-M1 (300a, 300b) via the base station operation unit 201. Thereby, interference from the macro base station 200a can be suppressed for each terminal 300-P1 (300e, 300f) of the pico base station 100a.

On the other hand, when the relative load ΔU_pico of the pico base station 100a is less than the threshold value ΔU_thr (S203, No), it is determined that the throughput of the terminal of the pico base station 100a is not lower than the throughput of the terminal of the macro base station 200a. Then, it is determined whether the transmission power P_pdsch of each terminal 300-M1 (300a, 300b) connected to the macro base station 200a is equal to the reference power P_rs (S206). If they are equal (S206, Yes), the macro base station 200a determines that the radio resource allocation is not restricted for the terminal 300-M1, and ends the process of FIG. On the other hand, if they are not equal (S206, No), the macro base station 200a determines that the radio resource allocation is restricted for the terminal 300-M1, and updates the transmission power P_pdsch to P_rs (S207). In S206 and S207, since the relative load between the pico base station and the macro base station is low, processing for not controlling the transmission power is executed.
On the other hand, when the RNTP notified from the pico base station 100a to the macro base station 200a is 0 (S201, No), the process proceeds to step S206. As described above, in S204 to S207, the resource usage rate in the pico communication area is equal to or greater than a predetermined value, and the load on the pico base station is relatively large based on a predetermined criterion relative to the load on the macro base station. When it is determined that the wireless resource of the macro communication area is controlled.

In addition to the method of reducing the transmission power below the reference power, the following method can be used for the process of limiting the available radio resources. For example, a method for limiting a time frame that can be used for a base station to perform wireless communication with a terminal in a communication area, or a base station can be used for wireless communication with a terminal in a communication area. For example, a method of limiting the frequency block.

As described above, according to the pico base station 100a and the macro base station 200a according to the first embodiment of the present invention, the communication frequency between the pico base station 100a and the terminals 300-P1 (300e, 300f) is high, In addition, when the load on the pico base station 100a is higher than the load on the macro base station 200a, the macro base station 200a limits the allocated radio resources, so that the throughput of the terminal 300-P can be increased, and the macro base station The fairness of throughput of all communication terminals 300 including 200 and the pico base station 100 can be improved.

Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above-described embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.
For example, instead of calculating the PRB usage rate of the macro base station 200a with respect to the PRB usage rate of the pico base station 100a as the relative load of the pico base station 100a, the allocated radio resource setting unit 204 calculates the PRB of the pico base station 200a. A ratio of the PRB usage rate of the macro base station 100a to the usage rate may be calculated.

Also, the allocated radio resource setting unit 204 sets the transmission power to a transmission power smaller than a preset reference transmission power when it is determined to limit the allocation of radio resources to the terminal 300-M1. However, although the allocation is restricted, the present invention is not limited to this. For example, the allocation may be limited by setting a band that can be allocated to a band other than the notified priority band.

In this case, the priority band is a partial band obtained by dividing the system band into a plurality. Alternatively, the allocation may be restricted by setting the assignable time to a time other than ABS (Almost Blank Subframe). In this case, the macro base station 200a does not transmit data during the ABS time. Further, the above allocation restriction methods may be combined. Furthermore, the method for performing the allocation restriction may be changed for each terminal.

Moreover, the number of Active UEs can also be used as a load used in the present embodiment. When the number of Active UEs is used as a load, an OAM server is connected on the communication line NW. The OAM server has a function of counting the number of Active UEs from each pico base station 100 and each macro base station 200 connected to the communication line NW. The number of Active UEs can be used in each pico base station 100 and each macro base station 200 via the OAM server.
The above changes can be similarly made in the following embodiments.

[Second Embodiment]
The pico cell notifies the macro cell of RNTP = 1 when the resource usage rate estimated from the buffer size of the own cell, the transmission rate, and the estimated traffic generation amount is equal to or greater than the threshold value and the relative load of the pico cell is equal to or greater than the threshold value. . When the macro cell receives a notification that RNTP is 1, it restricts radio resource allocation for a predetermined time (suppresses transmission power).

Next, a second embodiment of the present invention will be described in detail with reference to the drawings.
[Description of configuration]
FIG. 6 is a block diagram showing the functions of each pico base station 400 and each macro base station 500 in the second embodiment. The pico base station will be described as a pico base station 400a, and the macro base station will be described as a macro base station 500a. Although not shown in the figure, the functions of the surrounding pico base stations are the same as the functions of the pico base station 400a. Similarly, the functions of the surrounding macro base stations are the same as the functions of the macro base station 500a.

The pico base station 400a in the second embodiment is different from the pico base station 100a in the first embodiment in that it has a priority band setting unit 406 instead of the priority band setting unit 106. Also, the macro base station 500a in the second embodiment has an allocated radio resource setting unit 505 instead of the allocated radio resource setting unit 205, as compared with the macro base station 200a in the first embodiment. Different. Hereinafter, the priority band setting unit 406 and the assigned radio resource setting unit 505 will be described.

Unlike the priority band setting unit 106, the priority band setting unit 406 newly has a function of estimating the number of data bits generated within a predetermined time from a change in the buffer size of the transmission buffer 104. Further, the priority band setting unit 406 has a function of estimating the resource usage rate of the pico base station 400a from the calculated number of data bits, the buffer size of the transmission buffer 104, and the load. Further, the priority band setting unit 406 determines whether to set the priority band of the pico base station 400a using the estimated resource usage rate of the pico base station 400a, and notifies the macro base station 500a of the determination result. It has a function. In the present embodiment, the PRB usage rate is used as a load, the priority band is a system band, and RNTP is used for notification of a determination result. Also, in the present embodiment, when the priority band setting unit 406 sets the priority band of the pico base station 400a, the RNTP of all RBs is set to 1 for notification, and when it is not set, the notification is not performed.

The allocated radio resource setting unit 505 has a function of determining whether or not the macro base station 500a limits the allocation of radio resources to the terminal 300-M1, using the RNTP notified from the pico base station 400a. Have. In this embodiment, when the allocated radio resource setting unit 505 determines to limit the allocation of radio resources to the terminal 300-M1, the terminal 300-M1 receives the notification until a predetermined time elapses after receiving the notification. On the other hand, the assignable band is set as the system band, and the transmission power is set to a transmission power smaller than a preset reference transmission power. Further, after a predetermined time has elapsed, for the terminal 300-M1, the band that can be allocated is set as the system band, and the transmission power is set to a preset reference transmission power.

[Description of operation]
FIG. 7 shows an operation procedure in which the priority band setting unit 406 determines whether or not to set the priority band of the pico base station 400a. The priority band setting unit 406 performs the operation illustrated in FIG. 7 for each period in which the PRB usage rate is notified from the macro base station 500a.
First, using the PRB usage rate of the pico base station 300-1 measured by the load measuring unit 103 and the management information of the transmission buffer 104, the transmission bit number TB per RB of the pico base station 400a is calculated according to Equation (1). (S301).

Next, the average value ΔS_ave of the traffic size arriving at the transmission buffer 104 of the pico base station 400a within the predetermined time T is updated according to the equation (4) (S302).
ΔS_ave = ω × ΔS + (1-ω) × ΔS_ave_previous (4)
ΔS is the data size that has arrived at the transmission buffer 104 between the time before the predetermined time T and the current time, ΔS_ave_previous is the average value of the traffic size before update, and ω is a weighting coefficient.

Next, the estimated PRB usage rate U_pico_est of the pico base station 400a is calculated according to Equation (5) (S303).
U_pico_est = MIN [1.0, {(BS_present + ΔS_ave) / TB} / (N_PRB × T)] (5)
According to Expression (5), until the transmission of the data staying in the transmission buffer at the current time and the data generated within the predetermined time T is completed with respect to the total number of PRBs that can be used until the predetermined time T elapses from the current time. It is possible to estimate the ratio of the number of PRB necessary for

Next, it is determined whether or not the estimated PRB usage rate U_pico_est of the pico base station 400a is greater than or equal to a threshold value U_thr (S304).
When the estimated PRB usage rate U_pico_est of the pico base station 400a is greater than or equal to the threshold value U_thr (S304, Yes), the relative load ΔU_pico of the pico base station 400a is calculated according to the equation (3) (S305), and ΔU_pico is the threshold value ΔU_thr It is determined whether or not this is the case (S306).
When the relative load ΔU_pico of the pico base station 400a is equal to or greater than the threshold value ΔU_thr (S306, Yes), the priority band setting unit 406 sets the RNTP of all RBs to 1 and notifies the macro base station 500a (S307). . Then, the process of FIG. 7 is complete | finished.

On the other hand, when the relative load ΔU_pico of the pico base station 400a is less than the threshold value ΔU_thr (No in S307), the process of FIG.
Also, when the estimated PRB usage rate U_pico_est of the pico base station 400a is less than the threshold value U_thr (S304, No), the processing in FIG. 7 ends.

FIG. 8 shows an operation procedure in which the allocated radio resource setting unit 505 of the macro base station 500a sets radio resources that can be allocated to each terminal 300-M1 connected to the macro base station 500a. The allocated radio resource setting unit 505 performs the operation illustrated in FIG. 8 every time it receives an RNTP from the pico base station 400a.
First, it is determined whether or not RNTP notified from the pico base station 400a to the macro base station 500a is 1 (S401).

When the RNTP notified from the pico base station 400a to the macro base station 500a is 1 (S401, Yes), the T_end calculated according to the equation (6) is set as the time for the macro base station 500a to release the suppression of the transmission power of the PDSCH. (S402).
T_end = t + T_icic (6)
t represents the current time, and T_icic represents the time for the macro base station 500a to suppress the transmission power of the PDSCH.

Next, it is determined whether the PDSCH transmission power P_pdsch of the terminal 300-M1 connected to the macro base station 500a is equal to the value obtained by subtracting P_offset (> 0 dB) from the reference power P_rs (S403). If equal (S403, Yes), the process of FIG. 8 is terminated. On the other hand, if they are not equal (S403, No), the transmission power P_pdsch is updated to a value obtained by subtracting P_offset (> 0 dB) from P_rs (S404).

Also, in FIG. 9, the allocated radio resource setting unit 505 determines whether to cancel the limitation of radio resources that can be allocated to the terminal 300-M1 connected to the macro base station 500a, and based on the determination result. This shows an operation procedure for setting radio resources that can be allocated to the terminal 300-M1. The assigned radio resource setting unit 505 performs the operation illustrated in FIG. 9 for each time frame.

First, it is determined whether or not the current time t is after a time T_end when the macro base station 500a cancels the suppression of transmission power (S501).
When the current time t is before the time T_end when the macro base station 500a cancels the suppression of transmission power (S501, No), the processing in FIG. 9 is terminated.
On the other hand, when the current time T is after the time T_end when the macro base station 500a cancels transmission power suppression (S501, Yes), the transmission power P_pdsch of each terminal 300-M1 connected to the macro base station 500a and the reference It is determined whether the power P_rs is equal (S502). If equal (S502, Yes), the process of FIG. 9 is terminated. On the other hand, when they are not equal (S502, No), the transmission power P_pdsch is updated to P_rs (S503).

As described above, according to the present embodiment, the communication frequency between the pico base station 400a and the terminal 300-P1 is also estimated using the estimated value of the number of data bits generated in the pico base station 400a. Compared with the embodiment, the estimation accuracy of the resource usage rate of the pico base station can be improved. Furthermore, according to the present embodiment, RNTP is notified only when macro base station 500 implements restriction of allocated radio resources. Therefore, the amount of signaling between base stations via the communication line NW can be suppressed as compared with the first embodiment of the present invention.

Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above-described embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.
For example, the resource usage rate estimation method according to the present embodiment can also be applied to the first embodiment. Thereby, the estimation accuracy of the estimated PRB usage rate of the pico base station 100a in the first embodiment can be improved.

Also, the allocated radio resource setting unit 505 in the present embodiment releases the radio resource restriction when a predetermined time has elapsed since the start of radio resource restriction, but is the same as in the first embodiment. In addition, the restriction may be released when any one of the criteria for implementing the restriction of the radio resource cannot be satisfied. Alternatively, in the first embodiment, as in the present embodiment, the restriction may be canceled when a predetermined time has elapsed since the start of the restriction. This can be similarly performed in the following embodiments.

[Third embodiment]
The pico cell determines whether the sum of the resource usage rates estimated from the buffer size and transmission rate for each terminal is greater than or equal to a threshold value, and notifies the determination result to the macro cell using RNTP. When the macro cell receives a notification that RNTP is 1, it determines whether the relative load of the pico cell is equal to or greater than a threshold value, and if so, restricts the allocation of radio resources (suppresses transmission power).

Next, a third embodiment of the present invention will be described in detail with reference to the drawings.
[Description of configuration]
FIG. 10 is a block diagram showing the functions of each pico base station 600 and each macro base station 700 in the third embodiment. 4 is a block diagram illustrating functions of each macro base station 500. FIG. The pico base station will be described as a pico base station 600a, and the macro base station will be described as a macro base station 700a. Although not shown in the figure, the functions of the surrounding pico base stations are the same as the functions of the pico base station 600a. Similarly, the functions of the surrounding macro base stations are the same as the functions of the macro base station 700a.

The pico base station 600a in the third embodiment is different from the pico base station 100a in the first embodiment in that it has a priority band setting unit 607 instead of the priority band setting unit 106, and a new edge The difference is that a terminal determination unit 606 is provided. Further, the function of each macro base station in the third embodiment is the same as the function of the macro base station 200 in the first embodiment. Hereinafter, the edge terminal determination unit 606 and the priority band setting unit 607 will be described.

The edge terminal determination unit 606 has a function of determining whether or not each terminal 300-P1 is an edge terminal using the channel quality information reported from each terminal 300-P1. In this embodiment, reference signal received power (RSRP: Reference ： Signal Received Power) is used as the channel quality information. The determination result is used by the priority band setting unit 607 via the base station operation unit 101.

The priority band setting unit 607 estimates the resource usage rate from the buffer size and transmission rate of the transmission buffer 104 for each terminal 300-P1 determined by the edge terminal determination unit 606 as an edge terminal, and the estimated resource usage rate of each edge terminal And the resource usage rate of the pico base station 600a is estimated. Further, it has a function of determining whether or not to set the priority band of the pico base station 600a using the estimated resource usage rate of the pico base station 600a and notifying the macro base station 700a of the determination result. In the present embodiment, the load is the PRB usage rate, the priority band is the system band, and RNTP is used for notification of the determination result. Also, in the present embodiment, when the priority band setting unit 607 sets the priority band of the pico base station 600a, the RNTP of all RBs is set to 1 and notified, and when not set, the RNTP of all RBs is set. Set to 0 to notify.

[Description of operation]
FIG. 11 shows an operation procedure in which the edge terminal determination unit 606 of the pico base station 600a determines whether or not the terminal 300-P1 is an edge terminal. The edge terminal determination unit 606 performs the operation illustrated in FIG. 11 for each cycle in which the load measurement unit 103 notifies the macro base station 700a of the PRB usage rate.
First, the RSRP difference value ΔRSRP between the pico base station 600a of the terminal 300-P1-1 (300e) and the macro base station 700a is calculated according to the equation (7) (S601).
ΔRSRP = RSRP_pico-RSRP_macro (7)
RSRP_pico and RSRP_macro are the RSRP of the pico base station 600a and the RSRP of the macro base station 700a, respectively, reported to the pico base station 600a by the terminal 300-P1-1 (300e).

Next, it is determined whether or not the RSRP difference value ΔRSRP between the pico base station 600a of the terminal 300-P1-1 (300e) and the macro base station 700a is less than the threshold value ΔRSRP_thr (S602). If it is less than the threshold ΔRSRP_thr (S602, Yes), the terminal 300-P1-1 (300e) is determined to be an edge terminal (S603). On the other hand, when it is larger than the threshold value ΔRSRP_thr (S602, No), it is determined that the terminal 300-P1-1 (300e) is a center terminal (S604).
The edge terminal determination unit 606 performs the above operation for each terminal 300-P1 communicating with the pico base station 600a, and notifies the priority band setting unit 607 of the determination result.

FIG. 12 shows an operation procedure in which the priority band setting unit 607 of the pico base station 600a determines whether to set the priority band of the pico base station 600a. The priority band setting unit 607 performs the operation illustrated in FIG. 12 for each period in which the load measurement unit 103 notifies the macro base station 700a of the PRB usage rate.

First, the estimated PRB usage rate U_pico_est (i) is calculated for each terminal 300-P1 determined as an edge terminal by the edge terminal determination unit 606 according to Expression (8) (S701).
U_pico_est (i) = BS_present (i) / {TB (i) × N_PRB × T} (8)
i is an index for identifying the terminal 300-P1 determined to be an edge terminal. TB (i) is the number of transmission bits TB per RB of the edge terminal i, and is calculated by a simple average from the scheduling result of the scheduler 206. BS_present (i) represents the current buffer size of the edge terminal i.

Next, the estimated PRB usage rate U_pico_est of the pico base station 600a is calculated according to Equation (9) (S702).

N_edge is the number of terminals 300-P1 determined as edge terminals by the edge terminal determination unit 606.
Next, it is determined whether or not the estimated PRB usage rate U_pico_est of the pico base station 600a is equal to or greater than a threshold value U_thr (S703).

When the estimated PRB usage rate U_pico_est of the pico base station 600a is equal to or greater than the threshold value U_thr (S703, Yes), the communication frequency between the pico base station 600a and the terminal 300-P1 is between the current time and a predetermined time T. The priority band setting unit 607 determines that it is high, sets the RNTP of all RBs to 1, and notifies the macro base station 700a (S704). Then, the process of FIG. 11 is complete | finished.

Further, when the estimated PRB usage rate U_pico_est of the pico base station 100a is less than the threshold value U_thr (S703, No), communication between the pico base station 600a and the terminal 300-P1 is continued until a predetermined time T elapses from the current time. It is determined that the frequency is not high, and the priority band setting unit 607 sets the RNTP of all RBs to 0 and notifies the macro base station 700a (S705). Then, the process of FIG. 11 is complete | finished.

As described above, according to the present embodiment, when the frequency of communication between the terminal 300-P1 and the pico base station 600a is high, the macro base station 600a has a high communication frequency quality due to interference from the macro base station 700a. Since the station 700a limits the allocated radio resources, it is possible to improve the estimation accuracy of the resource usage rate of the pico base station as compared with the first embodiment of the present invention. *

In addition, this invention is not limited to the above embodiment. For example, the function of the edge terminal determination unit 606 may be removed from the configuration of the pico base station 600a. In this case, the priority band setting unit 607 calculates the estimated PRB usage rate for all terminals 300-P1 connected to the pico base station 600a, and notifies the macro base station 700a of the priority band using the sum total. Determine. In order to estimate the estimated PRB usage rate of the pico base station from the estimated PRB usage rate for each terminal 300-P, while improving the estimation accuracy of the resource usage rate of the pico base station as compared with the first embodiment, Compared with the third embodiment, the processing load of the pico base station can be reduced.

Further, the processing of the pico base station 600 in the third embodiment can also be performed by the macro base station 700. In this case, the macro base station 700 performs the processing of the edge terminal determination unit 606 and the priority band setting unit 607 for each of the other base stations described in the neighboring base station list included in the base station operation unit 101.

Other Embodiments In the above-described example, the communication area of the macro base station covers the communication area of the pico base station. However, the present invention is applicable to a wireless communication system in which a plurality of communication areas are adjacent to each other. Can be applied.
The radio resource setting method described in the above embodiment may be realized using a semiconductor processing apparatus including an ASIC (Application Specific Integrated Circuit). These processes may be realized by causing a computer system including at least one processor (eg, a microprocessor, MPU, DSP (Digital Signal Processor)) to execute a program. Specifically, one or a plurality of programs including an instruction group for causing the computer system to perform an algorithm related to the transmission signal processing or the reception signal processing may be created, and the programs may be supplied to the computer.

These programs can be stored using various types of non-transitory computer readable media and supplied to a computer. Non-transitory computer readable media include various types of tangible storage media (tangible storage medium). Examples of non-transitory computer-readable media include magnetic recording media (eg flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg magneto-optical discs), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable ROM), flash ROM, RAM (random access memory)) are included. The program may also be supplied to the computer by various types of temporary computer-readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

Further, the present invention can be modified as appropriate without departing from the spirit of the present invention. For example, the present invention can be applied to higher-level communication standards such as fourth-generation or higher communication standards (for example, LTE-Advanced, IMT-Advanced, WiMAX2).

A part or all of the above embodiment can be described as in the following supplementary notes, but is not limited thereto.
(Appendix 1)
A first communication area managed by a first radio base station and a second communication area managed by a second radio base station adjacent to or including part of the first communication area,
Compare the resource usage rate of the first communication area with a predetermined value,
Calculating the load of the first radio base station and the load of the second radio base station, comparing the relative load of the first radio base station and the second radio base station,
The resource usage rate of the first communication area is greater than or equal to the predetermined value, and the load of the first radio base station is based on a predetermined criterion compared to the load of the second radio base station Controlling the radio resources of the second communication area when it is determined that the second communication area is relatively large,
Radio resource setting method.
(Appendix 2)
The radio resource setting method according to appendix 1, further comprising a process of estimating a resource usage rate of the first communication area based on a transmission data size of the first radio base station.
(Appendix 3)
The estimation of the resource usage rate is based on the buffer size of the transmission data staying in the transmission buffer that manages the transmission data that the first radio base station transmits to each terminal in the first communication area, The transmission rate of one communication area,
Based on the estimation,
The radio resource setting method according to attachment 2.
(Appendix 4)
The estimation of the resource usage rate is based on a buffer size of transmission data staying in a transmission buffer that manages transmission data that the first radio base station transmits to each terminal in the first communication area, and
A transmission rate of the first communication area;
An average value of the data size of traffic data arriving at the transmission buffer within a predetermined time; and
Based on the estimation,
The radio resource setting method according to attachment 2.
(Appendix 5)
When the resource usage rate of the first communication area is lower than a predetermined value, or when it is determined that the relative load is low, the restriction on the radio resources of the second radio base station is canceled.
The radio resource setting method according to any one of appendices 1 to 4.
(Appendix 6)
When the radio resource of the second radio base station is limited by the process of controlling the radio resource of the second communication area, the restriction of the radio resource is released after a predetermined time has elapsed.
The radio resource setting method according to any one of appendices 1 to 5.
(Appendix 7)
When a plurality of terminals are in communication with the first radio base station in the first communication area,
The process of estimating the resource usage rate of the first communication area includes:
Edge when the value calculated based on the relative difference between the channel quality information of the first radio base station and the channel quality information of the second radio base station is smaller than a threshold value It is determined as a terminal, and if it is greater than or equal to the threshold value, it is determined as a center terminal
Calculating the resource utilization for the edge terminal;
The resource usage rate for each of the plurality of edge terminals is summed to obtain a new resource usage rate.
The radio resource setting method according to any one of appendices 1 to 6.
(Appendix 8)
The radio resource setting method according to any one of appendices 1 to 7, wherein the load is a bandwidth usage rate.
(Appendix 9)
The radio resource setting method according to any one of appendices 1 to 7, wherein the load is the number of terminals connected to the base station.
(Appendix 10)
The radio resource setting method according to appendix 7, wherein the channel quality is any one of RSRP, RSRQ, and SINR.
(Appendix 11)
A first radio base station that manages a first communication area, and a second radio base station that manages a second communication area that is adjacent to or part of the first communication area;
Means for comparing the resource usage rate of the first communication area with a predetermined value;
Means for calculating a load of the first radio base station and a load of the second radio base station, and comparing a relative load of the first radio base station and the second radio base station;
The resource usage rate of the first communication area is greater than or equal to the predetermined value, and the load of the first radio base station is based on a predetermined criterion compared to the load of the second radio base station And a means for controlling radio resources in the second communication area when it is determined that the radio resources are relatively large.
(Appendix 12)
The wireless communication system according to appendix 11, further comprising means for estimating a resource usage rate of the first communication area based on a transmission data size of the first wireless base station.
(Appendix 13)
The estimation of the resource usage rate is based on the buffer size of the transmission data staying in the transmission buffer that manages the transmission data that the first radio base station transmits to each terminal in the first communication area, The transmission rate of one communication area,
Based on the estimation,
The wireless communication system according to attachment 12.
(Appendix 14)
The estimation of the resource usage rate is based on a buffer size of transmission data staying in a transmission buffer that manages transmission data that the first radio base station transmits to each terminal in the first communication area, and
A transmission rate of the first communication area;
An average value of the data size of traffic data arriving at the transmission buffer within a predetermined time; and
Based on the estimation,
The wireless communication system according to attachment 12.
(Appendix 15)
When the resource usage rate of the first communication area is lower than a predetermined value, or when it is determined that the relative load is low, the restriction on the radio resources of the second radio base station is canceled.
15. The wireless communication system according to any one of appendices 11 to 14.
(Appendix 16)
When the radio resources of the second radio base station are limited by controlling the radio resources of the second communication area, the radio resource restriction is released after a predetermined time has elapsed.
The wireless communication system according to any one of appendices 11 to 15.
(Appendix 17)
When a plurality of terminals are in communication with the first radio base station in the first communication area,
Means for estimating a resource usage rate of the first communication area;
Edge when the value calculated based on the relative difference between the channel quality information of the first radio base station and the channel quality information of the second radio base station is smaller than a threshold value A means for determining a terminal and, if greater than or equal to a threshold value, determining a center terminal;
Means for calculating the resource utilization for the edge terminal;
The wireless communication system according to any one of appendices 11 to 16, further comprising means for adding the resource usage rates for each of the plurality of edge terminals to obtain a new resource usage rate.
(Appendix 18)
The wireless communication system according to any one of appendices 11 to 17, wherein the load is a bandwidth usage rate.
(Appendix 19)
The wireless communication system according to any one of appendices 11 to 17, wherein the load is the number of terminals connected to the base station.
(Appendix 20)
The wireless communication system according to appendix 17, wherein the channel quality is any one of RSRP, RSRQ, and SINR.
(Appendix 21)
A first radio base station that manages a first communication area, and a second radio base station that manages a second communication area that is adjacent to or part of the first communication area;
The first radio base station is
Means for comparing the resource usage rate of the first communication area with a predetermined value;
Means for notifying the second radio base station when the resource usage rate of the first communication area is greater than or equal to the predetermined value;
The second radio base station is
When the notification is received from the first radio base station, the load of the first radio base station and the load of the second radio base station are calculated, and the first radio base station and the first radio base station are calculated. Means for comparing the relative loads of the two radio base stations;
When it is determined that the load of the first radio base station is relatively large based on a predetermined criterion as compared with the load of the second radio base station, the radio of the second communication area A wireless communication system comprising means for controlling resources.
(Appendix 22)
A first radio base station that manages a first communication area, and a second radio base station that manages a second communication area that is adjacent to or part of the first communication area;
The first radio base station is
Means for comparing the resource usage rate of the first communication area with a predetermined value;
Means for calculating a load of the first radio base station and a load of the second radio base station, and comparing a relative load of the first radio base station and the second radio base station;
The resource usage rate of the first communication area is greater than or equal to the predetermined value, and the load of the first radio base station is based on a predetermined criterion compared to the load of the second radio base station Means for notifying the second radio base station when it is determined that the second radio base station is relatively large,
The second radio base station is
A radio communication system comprising means for controlling radio resources in the second communication area when receiving the notification from the first radio base station.
(Appendix 23)
A first communication area managed by a first radio base station and a second communication area managed by a second radio base station adjacent to or including part of the first communication area,
Compare the resource usage rate of the first communication area with a predetermined value,
Calculating the load of the first radio base station and the load of the second radio base station, comparing the relative load of the first radio base station and the second radio base station,
The resource usage rate of the first communication area is greater than or equal to the predetermined value, and the load of the first radio base station is based on a predetermined criterion compared to the load of the second radio base station A non-transitory computer-readable medium that causes a computer to execute a process of making a decision to control radio resources in the second communication area.
(Appendix 24)
Managing a second communication area that is adjacent to or part of the first communication area managed by the first radio base station;
When the resource usage rate of the first communication area is equal to or greater than the predetermined value and the load of the first radio base station is relatively large based on a predetermined criterion relative to its own load A radio base station that controls radio resources in the second communication area when determined.
(Appendix 25)
When managing the first communication area,
The resource usage rate of the first communication area is equal to or greater than the predetermined value, and the load of the radio base station manages a second communication area that is adjacent to or partially includes the first communication area. When it is determined that the load is relatively large based on a predetermined criterion as compared with the load of the other radio base station, the determination result for controlling the radio resource in the second communication area is given as the other base station. Radio base station to notify to.

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

This application claims priority based on Japanese Patent Application No. 2012-246579 filed on November 8, 2012, the entire disclosure of which is incorporated herein.

A pico base station B macro base station A1 terminal A2 terminal A3 terminal A4 terminal A5 terminal B1 terminal B2 terminal B3 terminal 10 wireless communication system 100a pico base station 100b pico base station 101 base station operation unit 102 reference signal generation unit 103 load measurement unit 104 transmission buffer 105 scheduler 106 priority band setting unit 200a macro base station 200b macro base station 201 base station operation unit 202 reference signal generation unit 203 load measurement unit 204 transmission buffer 205 allocation radio resource setting unit 206 scheduler 300a terminal 300-M1-1
300b terminal 300-M1-2
300c terminal 300-M2-1
300d terminal 300-M2-2
300e terminal 300-P1-1
300f terminal 300-P1-2
300g terminal 300-P2-1
300h terminal 300-P2-2
301 Terminal Operation Unit 302 Channel Quality Measurement Unit 400a Pico Base Station 406 Priority Band Setting Unit 500a Macro Base Station 505 Allocated Radio Resource Setting Unit 600a Pico Base Station 606 Edge Terminal Determination Unit 607 Priority Band Setting Unit 700a Macro Base Station

Claims (25)

1. A first communication area managed by a first radio base station and a second communication area managed by a second radio base station adjacent to or including part of the first communication area,
   Compare the resource usage rate of the first communication area with a predetermined value,
   Calculating the load of the first radio base station and the load of the second radio base station, comparing the relative load of the first radio base station and the second radio base station,
   The resource usage rate of the first communication area is greater than or equal to the predetermined value, and the load of the first radio base station is based on a predetermined criterion compared to the load of the second radio base station Controlling the radio resources of the second communication area when it is determined that the second communication area is relatively large,
   Radio resource setting method.
2. The radio resource setting method according to claim 1, further comprising a process of estimating a resource usage rate of the first communication area based on a transmission data size of the first radio base station.
3. The estimation of the resource usage rate is based on the buffer size of the transmission data staying in the transmission buffer that manages the transmission data that the first radio base station transmits to each terminal in the first communication area, The transmission rate of one communication area,
   Based on the estimation,
   The radio resource setting method according to claim 2.
4. The estimation of the resource usage rate is based on a buffer size of transmission data staying in a transmission buffer that manages transmission data that the first radio base station transmits to each terminal in the first communication area, and
   A transmission rate of the first communication area;
   An average value of the data size of traffic data arriving at the transmission buffer within a predetermined time; and
   Based on the estimation,
   The radio resource setting method according to claim 2.
5. When the resource usage rate of the first communication area is lower than a predetermined value, or when it is determined that the relative load is low, the restriction on the radio resources of the second radio base station is canceled.
   The radio resource setting method according to any one of claims 1 to 4.
6. When the radio resources of the second radio base station are limited by controlling the radio resources of the second communication area, the radio resource restriction is released after a predetermined time has elapsed.
   The radio resource setting method according to any one of claims 1 to 5.
7. When a plurality of terminals are in communication with the first radio base station in the first communication area,
   The process of estimating the resource usage rate of the first communication area includes:
   Edge when the value calculated based on the relative difference between the channel quality information of the first radio base station and the channel quality information of the second radio base station is smaller than a threshold value It is determined as a terminal, and if it is greater than or equal to the threshold value, it is determined as a center terminal,
   Calculating the resource utilization for the edge terminal;
   The resource usage rate for each of the plurality of edge terminals is summed to obtain a new resource usage rate.
   The radio resource setting method according to any one of claims 1 to 6.
8. The radio resource setting method according to any one of claims 1 to 7, wherein the load is a bandwidth usage rate.
9. The radio resource setting method according to any one of claims 1 to 7, wherein the load is the number of terminals connected to the base station.
10. The radio resource setting method according to claim 7, wherein the channel quality is one of RSRP, RSRQ, and SINR.
11. A first radio base station that manages a first communication area, and a second radio base station that manages a second communication area that is adjacent to or part of the first communication area;
    Means for comparing the resource usage rate of the first communication area with a predetermined value;
    Means for calculating a load of the first radio base station and a load of the second radio base station, and comparing a relative load of the first radio base station and the second radio base station;
    The resource usage rate of the first communication area is greater than or equal to the predetermined value, and the load of the first radio base station is based on a predetermined criterion compared to the load of the second radio base station And a means for controlling radio resources in the second communication area when it is determined that the radio resources are relatively large.
12. The wireless communication system according to claim 11, further comprising means for estimating a resource usage rate of the first communication area based on a transmission data size of the first wireless base station.
13. The estimation of the resource usage rate is based on the buffer size of the transmission data staying in the transmission buffer that manages the transmission data that the first radio base station transmits to each terminal in the first communication area, The transmission rate of one communication area,
    Based on the estimation,
    The wireless communication system according to claim 12.
14. The estimation of the resource usage rate is based on a buffer size of transmission data staying in a transmission buffer that manages transmission data that the first radio base station transmits to each terminal in the first communication area, and
    A transmission rate of the first communication area;
    An average value of the data size of traffic data arriving at the transmission buffer within a predetermined time; and
    Based on the estimation,
    The wireless communication system according to claim 12.
15. When the resource usage rate of the first communication area is lower than a predetermined value, or when it is determined that the relative load is low, the restriction on the radio resources of the second radio base station is canceled.
    The wireless communication system according to any one of claims 11 to 14.
16. When the radio resources of the second radio base station are limited by controlling the radio resources of the second communication area, the radio resource restriction is released after a predetermined time has elapsed.
    The wireless communication system according to any one of claims 11 to 15.
17. When a plurality of terminals are in communication with the first radio base station in the first communication area,
    Means for estimating a resource usage rate of the first communication area;
    Edge when the value calculated based on the relative difference between the channel quality information of the first radio base station and the channel quality information of the second radio base station is smaller than a threshold value A means for determining a terminal and, if greater than or equal to a threshold value, determining a center terminal;
    Means for calculating the resource utilization for the edge terminal;
    The radio communication system according to any one of claims 11 to 16, further comprising means for adding the resource usage rates for each of the plurality of edge terminals to obtain a new resource usage rate.
18. The wireless communication system according to any one of claims 11 to 17, wherein the load is a bandwidth usage rate.
19. The wireless communication system according to claim 11, wherein the load is the number of terminals connected to the base station.
20. The wireless communication system according to claim 17, wherein the channel quality is any one of RSRP, RSRQ, and SINR.
21. A first radio base station that manages a first communication area, and a second radio base station that manages a second communication area that is adjacent to or part of the first communication area;
    The first radio base station is
    Means for comparing the resource usage rate of the first communication area with a predetermined value;
    Means for notifying the second radio base station when the resource usage rate of the first communication area is greater than or equal to the predetermined value;
    The second radio base station is
    When the notification is received from the first radio base station, the load of the first radio base station and the load of the second radio base station are calculated, and the first radio base station and the first radio base station are calculated. Means for comparing the relative loads of the two radio base stations;
    When it is determined that the load of the first radio base station is relatively large based on a predetermined criterion as compared with the load of the second radio base station, the radio of the second communication area A wireless communication system comprising means for controlling resources.
22. A first radio base station that manages a first communication area, and a second radio base station that manages a second communication area that is adjacent to or part of the first communication area;
    The first radio base station is
    Means for comparing the resource usage rate of the first communication area with a predetermined value;
    Means for calculating a load of the first radio base station and a load of the second radio base station, and comparing a relative load of the first radio base station and the second radio base station;
    The resource usage rate of the first communication area is greater than or equal to the predetermined value, and the load of the first radio base station is based on a predetermined criterion compared to the load of the second radio base station Means for notifying the second radio base station when it is determined that the second radio base station is relatively large,
    The second radio base station is
    A radio communication system comprising means for controlling radio resources in the second communication area when receiving the notification from the first radio base station.
23. A first communication area managed by a first radio base station and a second communication area managed by a second radio base station adjacent to or including part of the first communication area,
    Compare the resource usage rate of the first communication area with a predetermined value,
    Calculating the load of the first radio base station and the load of the second radio base station, comparing the relative load of the first radio base station and the second radio base station,
    The resource usage rate of the first communication area is greater than or equal to the predetermined value, and the load of the first radio base station is based on a predetermined criterion compared to the load of the second radio base station A non-transitory computer-readable medium that causes a computer to execute a process of making a decision to control radio resources in the second communication area.
24. Managing a second communication area that is adjacent to or part of the first communication area managed by the first radio base station;
    When the resource usage rate of the first communication area is equal to or greater than the predetermined value and the load of the first radio base station is relatively large based on a predetermined criterion relative to its own load A radio base station that controls radio resources in the second communication area when determined.
25. When managing the first communication area,
    The resource usage rate of the first communication area is equal to or greater than the predetermined value, and the load of the radio base station manages a second communication area that is adjacent to or partially includes the first communication area. When it is determined that the load is relatively large based on a predetermined criterion as compared with the load of the other radio base station, the determination result for controlling the radio resource in the second communication area is given as the other base station. Radio base station to notify to.

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