JP7094315B2 - Base stations, communication systems, base station control methods and programs - Google Patents

Description

The present invention relates to a mobile communication base station, a communication system, a control method and a program of the base station.

Conventionally, there is known a mobile communication system in which a plurality of base stations that perform wireless communication with a terminal device (also referred to as a “user device (UE)”) in different frequency bands are mixed in a common area. For example, Non-Patent Document 1 describes a base station (eNodeB) that uses a fourth-generation LTE (Long Term Evolution) wireless communication system (hereinafter, also referred to as “LTE system”), and a newer generation (for example, the fifth generation). An NSA (Non-StandAlone) type mobile communication system in which base stations (gNodeB) using a wireless communication system (hereinafter also referred to as “NR system”) of the following “NR” are mixed in a common area is disclosed. Has been done. In this NSA mobile communication system, the terminal device can communicate user data by the LTE method and the NR method via each base station.

There is a technique (cell capacity control) for controlling the number of terminals accommodated in each cell formed by each base station (number of simultaneous connections) in a mobile communication system in which the above-mentioned plurality of base stations are mixed in a common area. .. For example, a technique for controlling the number of terminals accommodated (number of simultaneous connections) between a plurality of base stations (between frequency bands), interference from a base station with a desired radio beam from a connected base station in downlink communication from the base station. A technology called Interference Rejection Combining (IRC) that suppresses radio wave interference and interference from signals for other users at connected base stations with a terminal device, technology for controlling the transmission power of a base station, and between multiple base stations. Technology for adjusting the cell size with, and technology for collecting cell information of each base station with a management device such as NMS (Network Management System) installed outside the base station and controlling the parameters of the cell of the base station. Are known.

3GPP TR 38.801 V14.0.0 (2017-03), Technical Specification Group Radio Access Network; Study on new radio access technology: Radio access architecture and interfaces (Release 14)

However, the conventional cell capacity control technique in a mobile communication system in which a plurality of base stations are mixed in a common area functions when the wireless communication capabilities between the plurality of cells are equivalent to each other. Therefore, it does not function when the wireless communication capabilities between a plurality of cells are different from each other, such as between the cell of the LTE base station and the cell of the NR base station described above, and the capacity of the cell (terminal device). The number of accommodations and the number of simultaneous connections) may not be controlled properly. Further, even when a plurality of base stations of the same method coexist in a common area, there is a possibility that appropriate control cannot be performed among a plurality of cells having different bandwidths formed in the common area.

Further, when controlling from an external management device such as the NMS, it takes time to collect cell information and determine the cell control content based on the collected information, or the base station control is insufficient. On the contrary, the control of the base station may be excessive, and the capacity of the cell may not be appropriately and promptly controlled so as to correspond to the change in the number and distribution of the terminal devices in the cell.

The mobile communication base station according to one aspect of the present invention is based on a measurement report received from an antenna capable of controlling a directional beam and one or more terminal devices located in a cell formed by the base station. At least one of the acquisition unit that acquires the wireless communication performance information of the cell, the number of simultaneously connected terminal devices in the own cell based on the wireless communication performance information, and the throughput of the terminal device in the downlink of the own cell. Is provided with a control unit that controls at least one of the direction and shape of the directional beam of the antenna so that

In the base station, the radio communication performance information is the average value and the maximum value of the radio propagation loss of the propagation path between the base station and the terminal device in the cell and the number of terminal devices connected to the cell. The value, the utilization of the control channel element (CCE) in the radio resource of the cell, the throughput of the terminal device in the downlink of the cell, and the throughput of the terminal device in the uplink of the cell may be included.
In the base station, when the control unit determines that the downward tilt angle of the directional beam of the antenna from a predetermined reference direction is equal to or larger than a predetermined maximum downward tilt angle, the control unit determines the downward tilt angle of the antenna. The target tilt angle corresponding to the maximum throughput in the plurality of acquired data of the throughput of the terminal device in the downlink of the cell may be controlled.
In the base station, the control unit determines that the downward tilt angle of the directional beam of the antenna from a predetermined reference direction is equal to or larger than a predetermined maximum downward tilt angle, and the average value of the radio propagation loss is predetermined. When it is determined that the loss threshold value is equal to or higher than the loss threshold value of, the downward tilt angle of the antenna may be controlled to the target tilt angle corresponding to the minimum propagation loss in the cell.
In the base station, when the upward tilt angle of the directional beam of the antenna from a predetermined reference direction becomes larger than the predetermined maximum upward tilt angle, the control unit sets the upward tilt angle of the antenna to the cell. The target tilt angle corresponding to the maximum value in the plurality of acquired data of the number of the terminal devices connected to the terminal device may be controlled.
In the base station, the control unit has a tilt angle upward from a predetermined reference direction of the directional beam of the antenna larger than a predetermined maximum upward tilt angle, and an average value of the radio propagation loss is a predetermined loss. When it is determined that the value exceeds the threshold value, the upward tilt angle of the antenna may be controlled to the target tilt angle corresponding to the maximum value in the plurality of acquired data of the number of the terminal devices connected to the cell. good.
In the base station, the control unit is based on the wireless communication performance information when the average value of the number of terminal devices connected to the cells of the base station becomes larger than a predetermined control start threshold value. A predetermined control in which beam control for controlling at least one of the direction and shape of the directional beam of the antenna is started, and the average value of the number of terminal devices connected to the cell of the base station is smaller than the control start threshold value. The beam control may be stopped when it becomes smaller than the stop threshold value.

A communication system according to another aspect of the present invention includes any of the above base stations and one or more terminal devices that perform wireless communication with any of the above base stations.

A base station control method according to still another aspect of the present invention is a control method for controlling a mobile communication base station having an antenna capable of controlling a directional beam. This control method is based on acquiring the wireless communication performance information of the cell based on the measurement report received from one or a plurality of terminal devices located in the cell formed by the base station, and based on the wireless communication performance information. Therefore, at least one of the direction and shape of the directional beam of the antenna so that at least one of the number of simultaneously connected terminal devices in the own cell and the throughput of the terminal device in the downlink of the own cell are the target values. Including controlling.

A program according to still another aspect of the present invention is a program executed by a computer or a processor provided in a mobile communication base station having an antenna capable of controlling a directional beam. This program includes a program code for acquiring wireless communication performance information of the cell based on a measurement report received from one or a plurality of terminal devices located in the cell formed by the base station, and the wireless communication performance information. Based on, the direction and shape of the directional beam of the antenna so that at least one of the number of simultaneously connected terminal devices in the own cell and the throughput of the terminal device in the downlink of the own cell becomes the target value. Includes program code to control at least one.

In the control method and program of the base station, the radio communication performance information includes the average value of the radio propagation loss of the propagation path between the base station and the terminal device in the cell and the terminal connected to the cell. The average and maximum number of devices, the utilization of the control channel element (CCE) in the radio resource of the cell, the throughput of the terminal device in the downlink of the cell, and the throughput of the terminal device in the uplink of the cell. May include.
Here, when it is determined that the downward tilt angle of the directional beam of the antenna from the predetermined reference direction is equal to or larger than the predetermined maximum downward tilt angle, the downward tilt angle of the antenna is set to the downward link of the cell. The target tilt angle corresponding to the maximum throughput in the plurality of acquired data of the throughput of the terminal device may be controlled.
Further, it is determined that the downward tilt angle of the directional beam of the antenna from the predetermined reference direction is equal to or greater than the predetermined maximum downward tilt angle, and that the average value of the radio propagation loss is equal to or greater than the predetermined loss threshold value. At that time, the downward tilt angle of the antenna may be controlled to the target tilt angle corresponding to the minimum propagation loss in the cell.
In the control method and program of the base station, when the upward tilt angle of the directional beam of the antenna from a predetermined reference direction becomes larger than the predetermined maximum upward tilt angle, the upward tilt angle of the antenna is set to the cell. The target tilt angle corresponding to the maximum value in the plurality of acquired data of the number of the terminal devices connected to the terminal device may be controlled.
In the control method and program of the base station, the upward tilt angle of the directional beam of the antenna from a predetermined reference direction is larger than the predetermined maximum upward tilt angle, and the average value of the radio propagation loss is a predetermined loss. When it is determined that the target tilt angle is equal to or higher than the threshold value, the upward tilt angle of the antenna may be controlled to the target tilt angle corresponding to the maximum value in the plurality of acquired data of the number of the terminal devices connected to the cell. good.
In the control method and program of the base station, when the average value of the number of terminal devices connected to the cell of the base station becomes larger than a predetermined control start threshold value, the said based on the wireless communication performance information. A predetermined control in which beam control for controlling at least one of the direction and shape of the directional beam of the antenna is started, and the average value of the number of terminal devices connected to the cell of the base station is smaller than the control start threshold value. The beam control may be stopped when it becomes smaller than the stop threshold value.

In the base station, the communication system, the control method and program of the base station, the antenna may be an array antenna in which a plurality of antenna elements capable of controlling the phase and strength of a transmitted / received signal are two-dimensionally arranged. ..

According to the present invention, the capacity of a cell is appropriately and responsively controlled so as to respond to changes in the number and distribution of terminal devices in the cell of the base station without going through an external device that controls the base station. Can be done.

Explanatory drawing which shows an example of the mobile communication system which concerns on embodiment. The block diagram which shows one configuration example of the base station of an embodiment. The flowchart which shows an example of the capacity control of a cell in the base station of embodiment. The flowchart which shows the other example of the capacity control of the cell in the base station of embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory diagram showing an example of a mobile communication system according to the present embodiment.
The mobile communication system of the present embodiment includes base stations 20 and 30 connected to the core network 10 of the cellular mobile communication network. The communication system may include a user device (hereinafter referred to as "UE") 40, 40'as a terminal device that is a mobile station capable of wirelessly communicating with the base station 20.

The core network 10 of the present embodiment is an LTE core network (EPC: Evolved Packet Core) corresponding to the 4th generation LTE system. The core network 10 may be an NR core network corresponding to the NR (New Radio) method in the next generation (fifth generation). The NR core network may also support the 4th generation LTE system. Further, the core network 10 may be an LTE core network (EPC: Evolved Packet Core) corresponding to the NR method, or a core having both NR core network and LTE core network (EPC) functions separately. It may be a network.

The base stations 20 and 30 are provided in a common area, and cells 20A and 30A are formed in the common area, respectively. For example, the base stations 20 and 30 are arranged so that the center positions of the cells 20A and 30A are the center positions of the common area, respectively, and at least a part of the cells 20A and 30A overlap each other in a layered cell configuration. .. Each of the base stations 20 and 30 includes a plurality of sets of antennas and radio devices, and forms a plurality of sector cells having different orientations (for example, three sector cells having different orientations in the horizontal direction by 120 degrees).

In the present embodiment, the base station 20 is an LTE base station (for example, frequency: f20 and bandwidth: ₂₀ MHz eNodeB) corresponding to the Massive MIMO (MM) transmission method described later. The base station 30 is not a Massive MIMO (MM) transmission system, but an LTE system base station that supports normal MIMO (for example, MIMO with a combination of a transmitting antenna and a receiving antenna of 2 × 2, 4 × 4 or 8 × 8). (For example, frequency: f ₃₀ (<f ₂₀ ) and bandwidth: 20 MHz eNodeB).

The base stations 20 and 30 may be base stations (gNodeB) corresponding to the NR system, respectively. For example, the base station 20 is an NR-type base station (gNodeB) compatible with the Massive MIMO (MM) technique described later, and the base station 30 is a normal MIMO (for example, a combination of a transmitting antenna and a receiving antenna is 2 × 2, 4). It may be an NR type base station (gNodeB) corresponding to x4 or 8 × 8 MIMO). When the core network 10 is an NSA (Non-Standalone) type core network, the base station 20 is an NR type base station (gNodeB) compatible with the Massive MIMO (MM) technique described later, and the base station 30 is 2 ×. It may be an LTE base station (eNodeB) compatible with 2 MIMO.

The base stations 20 and 30 use different frequency bands from each other to perform wireless communication with the UEs 40 and 40'in the cells 20A and 30A, respectively. The UE 40 in the figure is a UE that is in the cell 20A of the base station 20 and is connected to the base station 20, and the UE 40'is in the cell 30A of the base station 30 and is connected to the base station 30. UE. In the following description, when the UE 40 and the UE 40'are described without distinction, they are described as the UE 40.

In the present embodiment, the base station 20 is an LTE base station (eNodeB) that wirelessly communicates with the UE ₄₀ using the LTE frequency band f20, and can support simultaneous connection of a large number of UEs by Massive MIMO (MM). , It is equipped with an array antenna in which a plurality of antenna elements capable of controlling the phase and strength of the transmitted / received signal are two-dimensionally arranged. Here, Massive MIMO (MM) is a super-multi-element composed of many antenna elements in a MIMO transmission method in which radio signals are spatially multiplexed and transmitted by using antennas of a plurality of antenna elements for transmission and reception. By adopting an antenna, it is possible to compensate for the propagation loss of radio waves when using a high frequency band, and it is a technology that realizes the formation of a sharp directional beam and the simultaneous transmission of a stream with more UEs. On the other hand, the base station 30 wirelessly communicates with the UE 40'using the LTE frequency band f ₃₀ (<f ₂₀ ), which is the same as the base station 20, but is normal without applying Massive MIMO (MM). It is an LTE base station (eNodeB) that uses MIMO (for example, MIMO in which the combination of a transmitting antenna and a receiving antenna is 2 × 2, 4 × 4 or 8 × 8) transmission method.

As the frequency band of the LTE system, for example, the LTE band assigned as "E-UTRA operating bands" in the technical specification of 3GPP: TS 36.101 (for example, band 1 (B1), band 3 (B3), band 8). (B8), band 28 (B28), band 41 (B41), band 42 (B42)) can be assigned and used in a frequency band having a predetermined bandwidth. As the frequency band when the NR method is applied, for example, a frequency band having a predetermined bandwidth in any of 3.7 GHz band, 4.5 GHz band, and 28 GHz band can be assigned and used.

The base stations 20 and 30, respectively, are a control / base band connected to an optical overhang radio unit (RRH) having an antenna and an optical overhang radio unit (RRH) via a high-speed transmission cable such as an optical fiber cable. It may be configured by using a device (BBU: Base Band Unit), and the RRH antenna of each base station may be arranged so as to be at the center position of the common area. Further, the base stations 20 and 30 may be configured as individual devices separated from each other, or at least a part of the base stations 20 and 30 may be integrally configured.

In this embodiment, the base stations 20 and 30 are fixed base stations that are fixedly arranged on the ground or the sea, but the base stations 20 and 30 may be mobile base stations.

The UEs 40 and 40'may be mobile stations that can be carried and used by users such as mobile phones and smartphones, and various devices such as vehicles and home appliances as long as they can wirelessly communicate with the base stations 20 and 30. It may be a terminal device such as a communication terminal module incorporated in an instrument, a machine, or the like. Further, the UE 40 may be a large amount of low-cost IoT (Internet of Things) devices in mMTC (Massive Machine-Type Communications) envisioned in the 5th generation mobile communication system.

The UE 40 located in the common area where the plurality of cells 20A and 30A are formed has, for example, the reception result of the radio signal received from the base stations 20 and 30 at the time of power-on, the network identification information and the priority stored in advance in the UE. Based on control information such as information, an initial connection request (attach request) is transmitted to the base station 20 or the base station 30 to connect to the cell 20A or the cell 30A. Further, the UE 40 located in the common area with the power turned on has the reception result of the radio signal received from the base stations 20 and 30 and the UE 40 in advance in the UE when the connection to the cell 20A or the cell 30A is disconnected. Based on the stored network identification information and control information such as priority information, a reselection request is transmitted to the base station 20 or the base station 30 to connect to the cell 20A or the cell 30A.

In a cell configuration in which a plurality of cells 20A and 30A are formed in a common area as shown in FIG. 1, when the conventional control of mobility load balancing (MLB: Mobility Load Balancing) between base stations is applied, the following problems are solved. There is.

When the cell (hereinafter also referred to as "non-MM cell") 30A of the base station (hereinafter also referred to as "non-MM base station") 30 that uses a normal MIMO transmission method instead of the Massive MIMO (MM) transmission method is a non-macro cell. For example, 200 is assumed as the upper limit of the number of UEs 40'connected to the MM cell 30A. Further, a cell (hereinafter also referred to as “MM cell”) 20A using the Massive MIMO (MM) transmission method is formed in an area having a large number of UEs (number of users) such as a station, an airport, an event venue, and a sports stadium (stadium). The base station has a Massive MIMO antenna equipped with a multi-element antenna array capable of connecting a large number of UEs 40, and is equipped with a radio having a beam forming technology capable of forming an antenna pattern (hereinafter referred to as "MM base"). Also called "station"). Since the non-MM base station 30 has a small number of MIMO multiplexes, the upper limit of the number of accommodations is lower than that of the MM base station 20. Therefore, it is assumed that the MM cell 20A of the MM base station 20 accommodates a number of UEs 40 corresponding to three to four times that of the non-MM cell 30A of the non-MM base station 30. On the other hand, in the conventional mobility load distribution (MLB) between base stations, the number of UEs 40 connected to the MM cell 20A of the MM base station 20 increases, the load becomes high, and the throughput of the UE 40 of the MM cell 20A decreases. In this case, the UE 40 to be offloaded from the MM cell 20A to the non-MM cell (macro cell) 30A of the non-MM base station 30 using another frequency band is randomly extracted in the MM cell 20A. Therefore, the UE 40 in the center of the MM cell 20A is pushed out to the non-MM cell 30A even though the load of the MM cell 20A is not heavy. On the contrary, the high load state of the MM cell 20A cannot be improved by randomly returning to the MM cell 20A from the non-MM cell 30A.

As described above, when the conventional control of mobility load balancing (MLB) between base stations is applied in the cell configuration in which the MM cell 20A and the non-MM cell 30A are formed in the common area, the load balancing does not work. There is a possibility that the capacities of the MM cell 20A and the non-MM cell 30A (the number of terminals accommodated and the number of simultaneous connections) cannot be appropriately controlled. In particular, when the mobility load balancing (MLB) between the base stations is controlled from an external management device such as NMS, the information of the cells 20A and 30A is collected and the control contents of the cells 20A and 30A are determined based on the collected information. It takes time, the control of the base stations 20 and 30 is insufficient, and conversely the control of the base stations 20 and 30 is excessive. There is a risk that the capacities of cells 20A and 30A cannot be controlled appropriately and responsively to accommodate changes in the distribution. Further, even when a plurality of base stations of the same NR system are mixed in a common area or a plurality of base stations of the same LTE system are mixed in a common area, the bandwidths formed in the common area are different from each other. There is a possibility that it cannot be properly controlled between the MM cell and the non-MM cell.

Therefore, in the present embodiment, the MM base station 20 acquires the wireless communication performance information of the MM cell 20A based on the measurement report received from the UE 40 in the MM cell 20A, and based on the wireless communication performance information, the MM base station 20 acquires the wireless communication performance information. The MM base station 20 is set so that at least one of the number of simultaneously connected UEs 40 in the own cell (MM cell) and the throughput (user throughput) of the UE 40 in the downlink of the own cell (MM cell) becomes the target value. It controls at least one of the direction and shape of the directional beam of the antenna. As a result, the capacity and downlink user throughput of the MM cell 20A can be appropriately adjusted to cope with changes in the number and distribution of UEs 40 in the MM cell 20A of the MM base station 20 without going through an external device such as an NMS. It can be controlled immediately.

In particular, the present inventor has a UE throughput when the number of UEs 40 connected to the MM cell 20A is 50 or more in controlling the directional beam of the antenna of the MM base station 20 based on the wireless communication performance information. As a result of analyzing the characteristics when the amount is decreasing, it was found that the following characteristics (A1) to (A6) can be seen.

(A1) The downlink (DL) UE throughput (DL User Th) is high, but the downlink (DL) traffic (Volume) is extremely small.
(A2) The loss (Pass Loss) of the radio propagation path is large.
(A3) The maximum number of UEs 40 (Max CU) connected to the MM cell 20A exceeds the design limit value of the MM base station 20 (wireless communication device).
(A4) The usage rate of the control channel element (CCE) in the radio resource of the MM cell 20A is high.
(A5) The downlink (DL) UE throughput (DL User Throughhput) is smaller than the uplink (UL) UE throughput (UL User Throughhput).
(A6) The consumption of the control channel element (CCE) has reached a level that causes a delay in accepting new calls.

Based on the above findings, the directivity of the antenna of the MM base station 20 is selected from the main performance indicators (KPI: Key Performance Indicator) calculated by the MM base station 20 and the like based on the measurement report (MR) received from the UE 40. As the wireless communication performance information used for beam control, the following six types of information (B1) to (B6) were selected. By controlling the directional beam of the antenna of the MM base station 20 using this information, the capacitance of the MM cell 20A can be controlled more accurately, appropriately and promptly.

(B1) Time average value (AVG Pass Loss) of the radio propagation loss of the propagation path between the MM base station 20 and the UE 40 in the MM cell 20A.
(B2) Time average value of the number of UEs 40 connected to the MM cell 20A (number of connected UEs) (AVG Number of RRC Connected User)
(B3) Maximum time value of the number of UEs 40 connected to the MM cell 20A (number of connected UEs) (MAX Number of RRC Connected User)
(B4) Utilization rate of the control channel element (CCE) in the radio resource of the MM cell 20A (CCE Usage Ratio).
(B5) UE40 throughput in downlink of MM cell 20A (DL User Throughhput)
(B6) UE 40 throughput in the uplink of MM cell 20A (UL User Throughhput)

FIG. 2 is a block diagram showing a configuration example of the base station 20 according to the present embodiment.
In FIG. 2, the MM base station 20 includes a base station device 200 and an antenna 210 capable of controlling a directional beam when transmitting and receiving radio waves. The base station device 200 includes a control unit 201, a wireless communication unit 202 that performs wireless communication between the UE 40 and the UE 40 via the antenna 210, a storage unit 203, and a data processing unit 204. The wireless communication unit 202 is, for example, a signal amplification unit that amplifies a transmission signal and a reception signal, a frequency conversion unit that converts the frequencies of the transmission signal and the reception signal into a predetermined frequency, a radio signal path switching unit, and a transmission / reception common unit (DUP:: It is equipped with a duplexer) and the like.

The antenna 210 of the base station 20 in the present embodiment is a Massive MIMO compatible antenna. For example, an array antenna in which a plurality of antenna elements (antenna elements) are two-dimensionally arranged is used, and the phase of the signal of each antenna element and the signal phase of each antenna element are used. It's like controlling the intensity to form a directional beam. Further, the antenna 210 may be a directional antenna in which a beam having directivity is formed by a single antenna such as a horn antenna. Further, the antenna 210 uses an array antenna in which antenna elements (antenna elements) composed of a plurality of directional antennas are arranged, and the signal phase of each antenna element is controlled to form a beam having directivity. You may. Further, the antenna 210 may be a sector antenna capable of electric tilt control.

The antenna 210 of the present embodiment is a Massive MIMO compatible antenna having a beamforming function capable of controlling the number of antenna beams, the beam width, and the beam direction in an array antenna in which antenna elements composed of a plurality of omnidirectional antennas are arranged. .. The beam width and beam direction of the antenna 210 need only be able to be controlled in at least one of the horizontal direction and the vertical direction. An antenna compatible with Massive MIMO has, for example, a maximum of 128 antenna elements, and can be assigned a dedicated radio wave to each user by using techniques such as beamforming and spatial multiplexing. While the conventional antenna shares the frequency with a plurality of users, the Massive MIMO compatible antenna occupies a dedicated frequency for each user. In the present embodiment, the beamforming function of the antenna 210 changes the width and direction of the beam of the antenna 210 to a desired width and direction to form one or more MM cells 20A having a desired shape at a desired position. Can be done.

In the present embodiment, the MM cell 20A is formed by narrowing the beam to the area of the station, airport, event venue, sports stadium, etc. where the UE 40 is concentrated and the communication traffic increases. As a result, higher communication quality can be obtained than when the entire area such as a station, an airport, an event venue, or a sports stadium is covered with a cell.

Beamforming control for controlling the direction and shape of the beam formed by the antenna 210 of the MM base station 20 can be performed, for example, as follows.

When transmitting data to the UE 40, the radio frequency communication unit 202 of the base station device 200 sends a transmission signal whose precoding control has been performed to the transmission baseband signal to the antenna 210 via the radio frequency (RF) device. Further, when the data is received from the UE 40, the received signal received by the RF device by the antenna 210 is acquired via the precoding control. The wireless communication unit 202 has a beamforming function for transmitting and receiving in a predetermined beam width and beam direction using the antenna 210 under the control of the control unit 201. Candidate data for a plurality of types of precoding (beam patterns) that can be used in the beamforming function are stored in the storage unit 203.

Here, the beamforming function by precoding is, for example, a set of phases (precoding) of signals of each antenna element of the antenna 210 so as to receive a beam transmitted in a specific direction or a beam from a specific direction. This is a function to prepare a plurality of types (N), select one from them, perform precoding control, and control the beam. In the present embodiment, the optimum precoding (beam pattern) is performed based on the wireless communication performance information of the MM cell 20A acquired based on the measurement report (MR) received from the UE 40 described above by the data processing by the data processing unit 204. ) Is selected. Then, the control unit 201 controls the beam of the antenna 210 according to the precoding selected by the data processing unit 204.

The control unit 201 of the base station apparatus 200 functions as each of the following means by reading out and executing a predetermined program.
(1) A means for acquiring wireless communication performance information of the MM cell 20A based on a measurement report (MR) received from a UE 40 located in the MM cell 20A formed by the MM base station 20.
(2) Based on the wireless communication performance information, at least one of the number of simultaneously connected UEs 40 in the MM cell (own cell) 20A and the throughput of the UE 40 in the downlink of the MM cell (own cell) 20A is the target number. A means of controlling at least one of the direction and shape of the directional beam of the antenna 210 so as to be.

Hereinafter, a dynamic control example of the capacity (accommodation number of terminal devices, number of simultaneous connections) of the MM cell 20A based on the wireless communication performance information in the MM base station 20 of the present embodiment will be described.

FIG. 3 is a flowchart showing an example of capacity control of the MM cell 20A in the MM base station 20 of the present embodiment. In this control example and the control example of FIG. 4 described later, the beam width is fixed, and the tilt angle from the reference direction of the beam is changed to control the beam so as to obtain the optimum beam pattern. , The tilt angle of the beam may be fixed, and at least one of the horizontal angle (for example, azimuth) and the beam width of the beam may be changed to control the beam so as to obtain an optimum beam pattern. Further, the beam may be controlled so as to obtain an optimum beam pattern by changing the tilt angle of the beam, the horizontal angle of the beam, and the beam width.

In this control and the control example of FIG. 4 described later, the setting parameters shown in Table 1 below are used.

Here, the “mean value of connected UEs” (AVG RRC CU) in Table 1 is a temporal average value of the number of connected UEs, and a plurality of connected UEs obtained for the number of connected UEs within the KPI acquisition cycle (ΔT _KPI ). The average value of the data. For example, the number of UEs 40 (number of connected UEs) in the RRC Connected State is sampled every second in one minute of the KPI acquisition cycle (ΔT _KPI ), and the data of the number of connected UEs of 60 of the sampling parameters is collected in CU1. Assuming that CU2, CU3, ..., CU60, the average value of connected UEs (AVG RRC CU) can be calculated by the following equation (1).

Further, the maximum value (MaxCU) of the number of connected UEs in FIG. 4 described later is the maximum value among a plurality of data obtained about the number of connected UEs within the KPI acquisition cycle (ΔT _KPI ), and is, for example, the above sampling parameter. It is the maximum value in the data of the number of connected UEs of 60.

Further, the average value (AVG Path Loss) of the propagation loss in FIG. 4 described later is the delay time (random access channel) of the RACH (random access channel) when a plurality of UEs 40 connect to the base station (gNodeB or eNodeB) within the KPI acquisition cycle. It is an average value of the propagation loss (Path Loss) of a plurality of UEs calculated from the data of Delay). The expected value of the average value (AVG Path Loss) of this propagation loss is "Expected AVG Path Loss".

Further, the maximum value (MAX Path Loss) of the propagation loss in FIG. 4 described later is a plurality of propagation losses (Path Loss) measured and calculated at that time by tilting up the antenna of the base station a plurality of times in advance. Is the maximum value of. In the example of FIG. 4 described later, the antenna of the base station is tilted up three times, and the propagation loss (Path Loss) at the time of the second tilt-up, which is the largest, is the maximum value of the propagation loss (MAX Path Loss). ) Is set.

In FIG. 3, the operating state of the MM base station 20 transitions between a normal operating state (normal operating mode) (S100) and a cell capacity adjustment control state (antenna beam automatic tilt control mode) (S200).

In the normal operating state (S100) of the MM base station 20, the tilt angle (E_Tilt Parameter Value) of the antenna 210 is set to the value designed when the MM base station 20 is installed. In this normal operating state, the MM base station 20 performs calculations as necessary based on the measurement report (MR) received from the UE 40 in the MM cell 20A at predetermined time intervals, whereby the MM cell 20A KPI data including wireless communication performance information is acquired and stored in the storage unit 203 of the MM base station 20.

Whether the control unit 201 of the MM base station 20 transitions to the cell capacity adjustment control state (S200) based on the average value of the connected UEs (AVG RRC CU) connected to the MM cell 20A included in the KPI data. Judge whether or not. For example, when the average value of connected UEs (AVG RRC CU) becomes larger than the predetermined control start threshold Th1 _AVG-CU (Evaluation Trigger AVG # of Connected User Threshold), the number of connected UEs in MM cell 20A rapidly increases. It is determined that the normal operation state (S100) is changed to the cell capacity adjustment control state (S200) (S110).

Further, the control unit 201 changes from the cell capacity adjustment control state (S200) to the normal operation state (S100) based on the connection UE average value (AVG RRC CU) connected to the MM cell 20A included in the KPI data. Judge whether or not to transition to return to. For example, when the average value of the connected UE (AVG RRC CU) becomes smaller than the predetermined control stop threshold, Th2 _AVG-CU (Automatic E_Tilt De-activation AVG # of Connected User Threshold), the connected UE of the MM cell 20A It is determined that the rapid increase state of the cell capacity adjustment control state has been resolved, and the state transitions from the cell capacity adjustment control state (S200) to the normal operation state (S100) (S120).

In the cell capacity adjustment control state (S200), first, the MM base station 20 is based on the measurement report (MR) received from the UE 40 in the MM cell 20A at a predetermined time interval ΔT _KPI (for example, 1 minute interval). By performing calculations as necessary, KPI data including wireless communication performance information of the MM cell 20A is acquired and stored in the storage unit 203 of the MM base station 20.

The control unit 201 of the MM base station 20 directs the direction of the directional beam of the antenna 210 downward from a predetermined reference direction based on the wireless communication performance information exemplified in Table 1 included in the KPI data stored in the storage unit 203. It is determined whether to adjust the tilt down to change the antenna 210 or to adjust the tilt up to change the direction of the directional beam of the antenna 210 from the predetermined reference direction to the upward direction.

In the example of FIG. 3, the control unit 201 executes the following determination H1 (S202) to determination H6 (S207) in that order. Judgment H1 (S202) to judgment H3 (S204) are judgments as to whether or not to tilt down, and judgment H4 (S205) to judgment H6 (S207) are judgments as to whether or not to tilt up.

H1 (S202): The average value of the connected UEs of the MM cell 20A is larger than the maximum value of the connected UEs corresponding to the upper limit of the cell capacity (AVG CU> N _CU-MAX ).
H2 (S203): The CCE usage rate of the MM cell 20A is smaller than the maximum value of the CCE usage rate corresponding to the upper limit of the cell capacity (CCE usage rate <CCE _MAX ).
H3 (S204): The downlink UE 40 throughput is smaller than the minimum target value of the downlink UE 40 throughput (DL user Throughput <THP _MIN-DL ).
H4 (S205): The downlink UE 40 throughput is larger than the expected downlink UE 40 throughput (DL user Throughput> THP _EXP-DL ).
H5 (S206): The CCE usage rate of the MM cell 20A is smaller than the value obtained by subtracting a predetermined offset (CCE offset) from the maximum value of the CCE usage rate corresponding to the upper limit of the cell capacity (CCE usage rate <CCE _MAX -CCE). offset).
H6 (S207): The average value of the connected UEs of the MM cell 20A is larger than the maximum value of the connected UEs corresponding to the upper limit of the cell capacity (AVG CU> N _CU-MAX ).

If any of the above-mentioned tilt-down necessity determination H1 (S202) to determination H3 (S204) is affirmative, the process shifts to the tilt-down control flow (S208 to S210), and determination H1 (S202) to determination. If all of H3 (S204) are negative, the process proceeds to the flow of determining the necessity of tilt-up (S205 to S207).

If all of the above-mentioned tilt-up necessity determination H4 (S205) to determination H6 (S207) are affirmative, the process proceeds to the tilt-up control flow (S211 to S213), and the determination H4 (S205) to determination H4 (S205) to If any of the determination H6 (S207) is negative, the process returns to the periodic acquisition (S201) of the KPI data.

In the tilt-down control flow, first, the set value of the tilt angle after tilt-down assuming that only a predetermined adjustment step unit (ΔTilt) is added is the lower limit value of the tilt angle adjustment range (Tilt _DOWN-MAX ). Is determined (S208).

The set value of the tilt angle after assuming tilt / down is the maximum downward tilt angle as the first angle threshold value which is the maximum value of the adjustment range of the downward tilt angle (hereinafter referred to as "lower limit value of down tilt") (Tilt _DOWN- . If _MAX ) is not reached (N in S208), beamforming control is executed so as to change the direction of the directional beam of the antenna 210 downward by the angle corresponding to the set value of the tilt angle after tilting down. (S209). After the execution, the process returns to the periodic acquisition (S201) of the KPI data.

On the other hand, if the tilt angle setting value after assuming tilt / down reaches or exceeds the lower limit of down tilt (Tilt _DOWN-MAX ) in the tilt angle adjustment range (Y in S208), the tilt angle. The set value of is changed to the set value of the target tilt angle corresponding to the maximum throughput in the plurality of acquired data of the throughput of the UE 40 in the downlink of the MM cell 20A, and corresponds to the set value of the target tilt angle after the change. Beamforming control is executed so that the tilt angle is reached (S210). After the execution, the process returns to the periodic acquisition (S201) of the KPI data.

Further, in the tilt-up control flow, first, the set value of the tilt angle after tilt-up assuming that only a predetermined adjustment step unit (ΔTilt) is subtracted is the maximum value of the adjustment range of the upward tilt angle. It is determined whether or not the maximum upward tilt angle (hereinafter referred to as "upper limit value of up tilt") (Tilt _UP-MAX ) as the two-angle threshold value has been reached (S211).

If the tilt angle setting value after tilt-up is not reached the upper limit of up-tilt (Tilt _UP-MAX ) in the tilt angle adjustment range (N in S211), the tilt angle setting after tilt-up is set. Beamforming control is executed so as to change the direction of the directional beam of the antenna 210 upward by an angle corresponding to the value (S212). After the execution, the process returns to the periodic acquisition (S201) of the KPI data.

On the other hand, if the set value of the tilt angle after assuming tilt-up reaches or exceeds the upper limit value (Tilt _UP-MAX ) of the up-tilt in the adjustment range of the tilt angle (Y in S211), the tilt angle. The set value of is changed to the set value of the target tilt angle corresponding to the maximum value in the plurality of acquired data of the number of UEs 40 connected to the MM cell 20A, and corresponds to the set value of the target tilt angle after the change. Beamforming control is executed so that the tilt angle is adjusted (S213). After the execution, the process returns to the periodic acquisition (S201) of the KPI data.

In the step of periodically acquiring the KPI data (S201), as described above, the cell capacity is adjusted based on the average value of the connected UEs (AVG RRC CU) connected to the MM cell 20A included in the KPI data. It is determined whether or not the transition is made so as to return from the control state (S200) to the normal operation state (S100). For example, when the average value of the connected UE (AVG RRC CU) becomes smaller than the predetermined control stop threshold, Th2 _AVG-CU (Automatic E_Tilt De-activation AVG # of Connected User Threshold), the connected UE of the MM cell 20A It is determined that the rapid increase state of the cell capacity adjustment control state has been resolved, and the cell capacity adjustment control state (S200) is changed to the normal operation state (S100) (S120).

FIG. 4 is a flowchart showing an example of capacity control of the MM cell 20A in the MM base station 20 of the present embodiment. In this control example, the content of control in the cell capacity adjustment control state (S300) is different. Since S100, S110, and S120 of FIG. 4 are the same as the control example of FIG. 3, their description will be omitted.

In the cell capacity adjustment control state (S300), first, the MM base station 20 is based on the measurement report (MR) received from the UE 40 in the MM cell 20A at a predetermined time interval ΔT _KPI (for example, 1 minute interval). By performing calculations as necessary, KPI data including wireless communication performance information of the MM cell 20A is acquired and stored in the storage unit 203 of the MM base station 20.

The control unit 201 of the MM base station 20 directs the direction of the directional beam of the antenna 210 downward from a predetermined reference direction based on the wireless communication performance information exemplified in Table 1 included in the KPI data stored in the storage unit 203. It is determined whether to adjust the tilt down to change the antenna 210 or to adjust the tilt up to change the direction of the directional beam of the antenna 210 from the predetermined reference direction to the upward direction.

In the example of FIG. 4, the control unit 201 executes the following determinations H1 (S302) to determination H5 (S306) in that order. Judgment H1 (S302) to Judgment H3 (S304) are judgments as to whether or not tilt down is performed, and judgment H4 (S305) to judgment H5 (S306) are judgments as to whether or not tilt up is performed.

H1 (S302): The average value of the connected UEs of the MM cell 20A is larger than the maximum value of the connected UEs corresponding to the upper limit of the cell capacity (AVG CU> N _CU-MAX ).
H2 (S303): The CCE usage rate of the MM cell 20A is smaller than the maximum value of the CCE usage rate corresponding to the upper limit of the cell capacity (CCE usage rate <CCE _MAX ).
H3 (S304): The downlink UE 40 throughput is smaller than the minimum target value of the downlink UE 40 throughput (DL user Throughput <THP _MIN-DL ).
H4 (S305): The downlink UE 40 throughput is greater than the expected downlink UE 40 throughput (DL user Throughput> THP _EXP-DL ).
H5 (S306): The decrease in the number of connected UEs per KPI data acquisition cycle (AVG CU_Before-AVG CU_Current) is larger than a predetermined threshold value (AVG CU_Before-AVG CU_Current> N _DEC-CU ).

If any of the above-mentioned tilt-down necessity determination H1 (S302) to determination H3 (S304) is affirmative, the process shifts to the tilt-down control flow (S307 to S310), and determination H1 (S302) to determination. If all of H3 (S304) are negative, the process proceeds to the flow of determining the necessity of tilt-up (S305 to S306).

If all of the above-mentioned tilt-up necessity determination H4 (S305) to determination H5 (S306) are affirmative, the flow shifts to the tilt-up control flow (S311 to S314), and the determination H4 (S305) to If any of the determination H5 (S306) is negative, the process returns to the periodic acquisition (S301) of the KPI data.

In the tilt-down control flow, first, the direction of the directional beam of the antenna 210 is changed downward by an angle corresponding to the set value of the tilt angle after tilt-down added by a predetermined adjustment step unit (ΔTilt). Beamforming control is executed so as to be performed (S307). After that, it is determined whether or not the set value of the tilt angle after tilting down reaches the lower limit value (Tilt _DOWN-MAX ) of the adjustment range of the tilt angle (S308).

If the set value of the tilt angle after tilting down does not reach the lower limit of down tilt (Tilt _DOWN-MAX ) in the tilt angle adjustment range (N in S308), the above KPI data is periodically acquired (S301). ).

On the other hand, if the set value of the tilt angle after tilting down reaches or exceeds the lower limit value (Tilt _DOWN-MAX ) of the down tilt in the tilt angle adjustment range (Y in S308), further propagation occurs. It is determined whether or not the average value of the loss (AVG Passloss) is smaller than the expected upper limit value (PL _AVG-EXP ) of the average propagation loss (path loss) as a predetermined loss threshold value (S309).

Here, if the average value of the propagation loss is smaller than the expected upper limit value (PL _AVG-EXP ) (Y in S309), the process returns to the periodic acquisition of the KPI data (S301). On the other hand, when the average value of the propagation loss is equal to or higher than the expected upper limit value (PL _AVG-EXP ) (N in S309), the tilt angle setting value is set to the target tilt angle setting value corresponding to the minimum propagation loss in the MM cell 20A. The beamforming control is executed so that the tilt angle corresponds to the set value of the target tilt angle after the change (S310). After the execution, the process returns to the periodic acquisition (S301) of the KPI data.

Further, in the tilt-up control flow, first, the direction of the directional beam of the antenna 210 is directed upward by an angle corresponding to the set value of the tilt angle after tilt-up subtracted by a predetermined adjustment step unit (ΔTilt). Beamforming control is executed so as to change (S311). After that, it is determined whether or not the set value of the tilt angle after the tilt-up reaches the upper limit value (Tilt _UP-MAX ) of the up-tilt in the adjustment range of the tilt angle (S312).

If the set value of the tilt angle after tilting up does not reach the upper limit value (Tilt _UP-MAX ) of the tilt angle adjustment range (N in S312), the above KPI data is periodically acquired (S301). ).

On the other hand, if the set value of the tilt angle after tilting up reaches or exceeds the upper limit value (Tilt _UP-MAX ) of the up tilt of the tilt angle adjustment range (Y in S312), further propagation occurs. It is determined whether or not the average value of the loss (AVG Passloss) is larger than the expected upper limit value (PL _AVG-EXP ) of the average propagation loss (path loss) as a predetermined loss threshold value (S313).

Here, when the average value of the propagation loss is equal to or less than the expected upper limit value (PL _AVG-EXP ) of the average propagation loss (path loss) (N in S313), the process returns to the periodic acquisition of the KPI data (S301). On the other hand, when the average value of the propagation loss is larger than the expected upper limit value (PL _AVG-EXP ) (Y in S313), the set value of the tilt angle is measured and calculated within the above-mentioned KPI acquisition cycle. The average value (AVG Pass Loss) of the propagation loss in the plurality of UEs 40 connected to the above is less than the expected upper limit value (PL _AVG-EXP , Exected AVG Pass Loss) and the maximum value of the propagation loss (Max Pass Loss). ) Is changed to a smaller target tilt angle, and beamforming control is executed so that the tilt angle corresponds to the set value of the changed target tilt angle (S314). After the execution, the process returns to the periodic acquisition (S301) of the KPI data.

In the step of periodically acquiring the KPI data (S301), as described above, the cell capacity is adjusted based on the average value of the connected UEs (AVG RRC CU) connected to the MM cell 20A included in the KPI data. It is determined whether or not a transition is made so as to return from the control state (S300) to the normal operation state (S100). For example, when the average value of the connected UE (AVG RRC CU) becomes smaller than the predetermined control stop threshold, Th2 _AVG-CU (Automatic E_Tilt De-activation AVG # of Connected User Threshold), the connected UE of the MM cell 20A It is determined that the rapid increase state of the cell capacity adjustment control state has been resolved, and the cell capacity adjustment control state (S300) is changed to the normal operation state (S100) (S120).

The control of steps S309 to S310 in FIG. 4 may be applied and executed instead of step S210 in the control example of FIG. 3, and the control of steps S313 to S314 of FIG. 4 may be applied in the control example of FIG. It may be applied and executed instead of step S213.

As described above, according to the present embodiment, the MM cell 20A of the MM base station 20 is not provided with a server such as an EMS (Element Management System) that manages and remotely controls the base station and an external device such as a remote control device. It is possible to appropriately and responsively control the cell capacity and the downlink user throughput so as to correspond to the change in the number and distribution of the UEs 40 in the cell.

The processing process described herein and the components of the communication system, base station and terminal device (UE, mobile station device, user terminal device, mobile device) can be implemented by various means. For example, these processes and components may be implemented in hardware, firmware, software, or a combination thereof. For example, in the above-mentioned processing in the base station of the present embodiment, a predetermined program is read and executed in the hardware described later, or a predetermined program preliminarily incorporated in the hardware described later is executed. It will be realized.

Regarding hardware implementation, means such as a processing unit used to realize the above steps and components in an entity (for example, various wireless communication devices, Node B, terminal, hard disk drive device, or optical disk drive device) One or more application-specific ICs (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors , Controllers, microprocessors, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, computers, or combinations thereof.

Further, for firmware and / or software implementation, means such as a processing unit used to realize the above components are programs (eg, procedures, functions, modules, instructions) that execute the functions described herein. , Etc.) may be implemented. In general, any computer / processor readable medium that clearly embodies the firmware and / or software code is a means such as a processing unit used to implement the steps and components described herein. May be used to implement. For example, firmware and / or software code may be stored in memory and executed by a computer or processor, for example in a control device. The memory may be mounted inside the computer or processor, or it may be mounted outside the processor. Further, the firmware and / or software code may be, for example, a random access memory (RAM), a read-only memory (ROM), a non-volatile random access memory (NVRAM), a programmable read-only memory (PROM), or an electrically erasable PROM (EEPROM). ), FLASH memory, floppy (registered trademark) discs, compact discs (CDs), digital versatile discs (DVDs), magnetic or optical data storage devices, etc. good. The code may be executed by one or more computers or processors, or the computers or processors may be made to perform functional embodiments described herein.

Further, the medium may be a non-temporary recording medium. Further, the code of the program may be read and executed by a computer, a processor, or another device or device machine, and the format is not limited to a specific format. For example, the code of the program may be any of source code, object code, and binary code, or may be a mixture of two or more of these codes.

Also, the description of the embodiments disclosed herein is provided to allow one of ordinary skill in the art to manufacture or use the present disclosure. Various amendments to this disclosure will be readily apparent to those of skill in the art and the general principles defined herein are applicable to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be recognized in the broadest range consistent with the principles and novel features disclosed herein.

10: Core network 20: MM base station 20A: MM cell 30: Non-MM base station 30A: Non-MM cell 200: Base station device 201: Control unit 202: Wireless communication unit 203: Storage unit 204: Data processing unit 210: Antenna

Claims (10)

It ’s a mobile communication base station.
With an antenna that can control the directional beam,
From the main performance index (KPI) of the cell calculated based on the measurement report received from one or more terminal devices in the cell formed by the base station, the cell is used as the wireless communication performance information of the cell. The average value of the radio propagation loss of the propagation path between the base station and the terminal device, the average value of the number of terminal devices connected to the cell, and the maximum number of terminal devices connected to the cell. Six types of information are selected and acquired: the value, the utilization rate of the control channel element (CCE) in the radio resource of the cell, the throughput of the terminal device in the downlink of the cell, and the throughput of the terminal device in the uplink of the cell. Acquisition department and
Based on the six types of information selected and acquired as the wireless communication performance information, the target is at least one of the number of simultaneously connected terminal devices in the own cell and the throughput of the terminal device in the downlink of the own cell. A base station including a control unit that controls at least one of the direction and shape of the directional beam of the antenna so as to have a value. In the base station of claim 1 ,
When the control unit determines that the downward tilt angle of the directional beam of the antenna is equal to or greater than the predetermined maximum downward tilt angle, the downward tilt angle of the antenna is set to the downlink of the cell. A base station characterized by controlling to a target tilt angle corresponding to the maximum throughput in a plurality of acquired data of the throughput of the terminal device in the above. In the base station of claim 2 ,
The control unit determines that the downward tilt angle of the directional beam of the antenna from the predetermined reference direction is equal to or greater than the predetermined maximum downward tilt angle, and the average value of the radio propagation loss is equal to or greater than the predetermined loss threshold value. A base station characterized in that the downward tilt angle of the antenna is controlled to a target tilt angle corresponding to the minimum propagation loss in the cell when it is determined to be. In the base station of claim 1, 2 or 3 ,
The control unit connects the upward tilt angle of the antenna to the cell when the upward tilt angle of the directional beam of the antenna from a predetermined reference direction becomes larger than the predetermined maximum upward tilt angle. A base station characterized in that the target tilt angle corresponding to the maximum value in the plurality of acquired data of the number of terminal devices is controlled. In the base station of claim 4 ,
The control unit determines that the upward tilt angle of the directional beam of the antenna from a predetermined reference direction is larger than the predetermined maximum upward tilt angle, and the average value of the radio propagation loss is equal to or higher than the predetermined loss threshold value. At that time, the base station is characterized in that the upward tilt angle of the antenna is controlled to the target tilt angle corresponding to the maximum value in the plurality of acquired data of the number of the terminal devices connected to the cell. .. In any of the base stations of claims 1 to 5 ,
The control unit
When the average value of the number of terminal devices connected to the cell of the base station becomes larger than a predetermined control start threshold value, the direction and shape of the directional beam of the antenna based on the wireless communication performance information Start beam control to control at least one,
The beam control is stopped when the average value of the number of terminal devices connected to the cell of the base station becomes smaller than a predetermined control stop threshold value smaller than the control start threshold value. base station. In any of the base stations of claims 1 to 6 ,
The antenna is a base station characterized by being an array antenna in which a plurality of antenna elements capable of controlling the phase and strength of a transmitted / received signal are two-dimensionally arranged. A communication system including the base station according to any one of claims 1 to 7 and a terminal device that performs wireless communication with the base station. A control method for controlling a mobile communication base station having an antenna capable of controlling a directional beam.
From the main performance index (KPI) of the cell calculated based on the measurement report received from one or more terminal devices in the cell formed by the base station, the cell is used as the wireless communication performance information of the cell. The average value of the radio propagation loss of the propagation path between the base station and the terminal device, the average value of the number of terminal devices connected to the cell, and the maximum number of terminal devices connected to the cell. Six types of information are selected and acquired: the value, the utilization rate of the control channel element (CCE) in the radio resource of the cell, the throughput of the terminal device in the downlink of the cell, and the throughput of the terminal device in the uplink of the cell. That and
Based on the six types of information selected and acquired as the wireless communication performance information, the target is at least one of the number of simultaneously connected terminal devices in the own cell and the throughput of the terminal device in the downlink of the own cell. Controlling at least one of the direction and shape of the directional beam of the antenna to be a value,
A control method characterized by including. A program executed by a computer or processor installed in a mobile communication base station having an antenna capable of controlling a directional beam.
From the main performance index (KPI) of the cell calculated based on the measurement report received from one or more terminal devices in the cell formed by the base station, the cell is used as the wireless communication performance information of the cell. The average value of the radio propagation loss of the propagation path between the base station and the terminal device, the average value of the number of terminal devices connected to the cell, and the maximum number of terminal devices connected to the cell. Six types of information are selected and acquired: the value, the usage rate of the control channel element (CCE) in the radio resource of the cell, the throughput of the terminal device in the downlink of the cell, and the throughput of the terminal device in the uplink of the cell. Program code for
Based on the six types of information selected and acquired as the wireless communication performance information, the target is at least one of the number of simultaneously connected terminal devices in the own cell and the throughput of the terminal device in the downlink of the own cell. A program code for controlling at least one of the direction and shape of the directional beam of the antenna so as to be a value.
A program characterized by including.

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