JP7183831B2 - Base station management device and program - Google Patents

Description

The present invention relates to a base station management device and program.

In a wireless communication system, a terminal connects to a base station by receiving a control signal from the base station. At this time, when a large number of terminals are unevenly connected to a specific base station and traffic increases (radio communication is congested), it becomes difficult for terminals existing in the area to connect to the base station.

For example, Patent Literature 1 describes a wireless communication system that optimizes the settings of other base stations according to the state of a specific base station.

WO2010/104143

When controlling a base station of a wireless communication system, for example, immediately after restarting the base station, requests from terminals (location registration requests, etc.) concentrate on the base station, increasing the load on the base station. Congestion is more likely to occur in wireless communication systems. Therefore, there is a demand for a technique capable of sufficiently preventing congestion while considering the restart of the base station and synchronizing the processing of the base station to be restarted and other base stations.

The present invention proposes a base station management apparatus capable of sufficiently preventing congestion when restarting a base station.

A base station management apparatus of the present invention comprises a communication unit that performs information communication with a target base station and an adjacent base station of the target base station, and a communication unit that performs information communication with the target base station when starting the target base station. The first start-up control information for stepwise increasing the transmission power of the base station is transmitted from the communication unit to the adjacent base station in synchronization with the stepwise increase of the transmission power of the target base station. a processing unit for transmitting, from the communication unit, second start-up control information for gradually decreasing the transmission power of the adjacent base station.

A program of the present invention comprises a communication step of performing information communication with a target base station and an adjacent base station of the target base station; transmitting first start-up control information for stepwise increasing the transmission power, and transmitting the adjacent base station to the adjacent base station in synchronization with the stepwise increase of the transmission power of the target base station; and a processing step of transmitting the second start-up control information for gradually decreasing the output power, and causing the computer operating as the base station management device to execute the processing step.

According to the present invention, it is possible to sufficiently prevent congestion when restarting a base station.

FIG. 1 is a schematic diagram showing an example of the configuration of a radio communication system according to the first embodiment of the present invention. FIG. 2 is a block diagram showing an example of the configuration of the base station management device according to the first embodiment of the present invention. FIG. 3 is a block diagram showing an example of the configuration of the base station according to the first embodiment of the present invention. FIG. 4 is a schematic diagram for explaining adjacent base station information. FIG. 5 is a schematic diagram for explaining transmission output information. FIG. 6 is a schematic diagram for explaining transmission power change time information. FIG. 7 is a sequence diagram showing operations of the wireless communication system. FIG. 8 is a schematic diagram for explaining temporal changes in transmission power until the restart target base station restarts. FIG. 9 is a schematic diagram for explaining temporal changes in transmission power until the transmission power of an adjacent base station reaches the maximum transmission power. FIG. 10 is a sequence diagram showing operations of the wireless communication system. FIG. 11 is a schematic diagram for explaining a change in transmission power over time until the transmission power of the restart target base station reaches the normal transmission power. FIG. 12 is a schematic diagram for explaining temporal changes in transmission power until the transmission power of an adjacent base station reaches the normal transmission power. FIG. 13A is a schematic diagram for explaining an operation in which each cover area changes step by step. FIG. 13B is a schematic diagram for explaining an operation in which each cover area changes step by step. FIG. 13C is a schematic diagram for explaining an operation in which each cover area changes step by step. FIG. 13D is a schematic diagram for explaining an operation in which each cover area changes step by step. FIG. 14 is a flow chart showing the processing flow of each part of the base station management device when the restart target base station is restarted. FIG. 15 is a flowchart showing the flow of processing of each part of the restart target base station when the restart target base station is restarted. FIG. 16 is a flow chart showing the processing flow of each part of the adjacent base station when the restart target base station is restarted. FIG. 17 is a flow chart showing the processing flow of each part of the base station management device until the transmission power of each base station returns to the normal transmission power. FIG. 18 is a flow chart showing the processing flow of each part of the restart target base station until the transmission power of each base station returns to the normal transmission power. FIG. 19 is a flow chart showing the processing flow of each part of the adjacent base station until the transmission power of each base station returns to the normal transmission power. FIG. 20A shows an example of an output change pattern when stopping a restart target base station. FIG. 20B shows an example of an output change pattern when stopping a restart target base station. FIG. 21A is a schematic diagram showing an output change pattern in which the number of registered terminals of a restart target base station is less than a threshold. FIG. 21B is a schematic diagram showing an output change pattern in which the number of registered terminals of the restart target base station is equal to or greater than the threshold. FIG. 22 is a flow chart showing an example of the processing flow of the base station management device. FIG. 23 is a flow chart showing an example of the processing flow of the base station management device. FIG. 24 is a schematic diagram for explaining an example of a method of selecting adjacent base stations using terminal location information. FIG. 25 is a flow chart showing an example of the processing flow of the base station management device when the restart target base station is stopped. FIG. 26 is a flow chart showing an example of the processing flow of the base station management apparatus after restarting the restart target base station. FIG. 27 is a schematic diagram showing the configuration of a wireless communication system according to the fifth embodiment.

DETAILED DESCRIPTION OF THE INVENTION Embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited by this embodiment, and when there are a plurality of embodiments, a combination of each embodiment is also included.

[First embodiment]
The configuration of the radio communication system according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram showing an example of the configuration of a radio communication system according to the first embodiment of the present invention.

As shown in FIG. 1, the wireless communication system 1 includes a first terminal 10-1, a second terminal 10-2, a third terminal 10-3, a fourth terminal 10-4, a fifth terminal 10- 5, a sixth terminal 10-6, a base station management apparatus 100, a first base station 200-1, a second base station 200-2, and a third base station 200-3. The first coverage area 300-1 is an area where communication with the first base station 200-1 is possible. The second coverage area 300-2 is an area where communication with the second base station 200-2 is possible. The third coverage area 300-3 is an area where communication with the third base station 200-3 is possible. Although six terminals and three base stations are shown in FIG. 1, this is an example and does not limit the present invention. Also, hereinafter, the first base station 200-1 to the third base station 200-3 may be collectively referred to as the base station 200. FIG.

The base station management device 100 and the first to third base stations 200-1 to 200-3 are connected to a network NW such as an IP (Internet Protocol) network. In the example shown in FIG. 1, a single base station management device 100 manages a plurality of base stations from first base station 200-1 to third base station 200-3. However, this is an example, and multiple base station management apparatuses 100 may exist in the present invention. Also, at least one of the first base station 200-1 to the third base station 200-3 may have the function of the base station management apparatus 100. FIG. That is, base station management apparatus 100 and base station 200 may be an integrated apparatus.

[Base station management device]
The configuration of the base station management device will be described with reference to FIG. FIG. 2 is a block diagram showing an example of the configuration of a base station management device.

As shown in FIG. 2, the base station management device 100 includes a communication section 110, a processing section 120, and a storage section . An input device 140 and a display device 150 are connected to the base station management device 100 .

The communication unit 110 performs information communication with equipment external to the base station management apparatus 100 . The communication unit 110 performs information communication with external devices via a network NW such as an IP network. The communication unit 110 is configured by a network IF (Interface) circuit having a LAN (Local Area Network) function, for example.

The processing unit 120 controls each unit of the base station management device 100 . The processing unit 120 executes processing based on requests from the outside. The processing unit 120 outputs requests, processing results, and the like to the outside as necessary. The processing unit 120 includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. In this case, the ROM stores a program for the CPU to control each part. The CPU reads a program stored in the ROM, secures a data area in the RAM, and executes the program, thereby controlling each unit of the base station management apparatus 100 . The processing unit 120 has a timekeeping function that acquires the current time (current date and time) with a predetermined accuracy.

The storage unit 130 stores various data. The storage unit 130 stores, for example, adjacent base station information, transmission power information, and transmission power change time information. The storage unit 130 may store a program for the processing unit 120 to control each unit. The storage unit 130 is configured by, for example, an HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like. Storage unit 130 may be configured with other semiconductor memory or the like.

The input device 140 receives various operations for the base station management device 100 from a user such as a system administrator. The input device 140 is not particularly limited, but is composed of a keyboard, a mouse, and the like.

The display device 150 displays various information. The display device 150 presents information output from the base station management device 100 to a user such as a system administrator. The display device 150 is not particularly limited, but may be a display including a liquid crystal display (LCD) or an organic EL (organic electro-luminescence) display. The display device 150 may be provided with a touch panel as the input device 140 .

In the example shown in FIG. 2, the input device 140 and the display device 150 are directly connected to the base station management device 100, but this is an example and does not limit the present invention. For example, the input device 140 and the display device 150 may be connected to an external management terminal (management personal computer) connected to the base station management device 100 via a network. In this case, the operation received by the input device 140 is input to the base station management device 100 via the management terminal. Information output from the base station management device 100 is input to the display device 150 via the management terminal.

[base station]
The configuration of the base station will be described with reference to FIG. FIG. 3 is a block diagram showing an example of the configuration of a base station.

As shown in FIG. 3 , base station 200 includes communication section 210 , processing section 220 , transmission output control section 230 , reception section 240 , transmission section 250 and antenna 260 .

The communication unit 210 performs information communication with devices outside the base station 200 . The communication unit 210 performs information communication with external devices via a network NW such as an IP network. The communication unit 210 is composed of a network IF circuit having a LAN function, for example.

The processing unit 220 controls each unit of the base station 200 . The processing unit 220 executes processing based on requests from the outside. The processing unit 220 outputs requests, processing results, and the like to the outside as necessary. The processing unit 220 is composed of, for example, a CPU, RAM, ROM, and the like. In this case, the ROM stores a program for the CPU to control each part. The CPU reads a program stored in the ROM, secures a data area in the RAM, and executes the program to control each part of the base station 200 . The processing unit 220 has a timekeeping function that acquires the current time (current date and time) with a predetermined accuracy. Moreover, it is desirable that the time obtained by the processing unit 220 of each base station 200 and the time obtained by the processing unit 120 of the base station management device 100 are synchronized so that the time difference is less than a predetermined value. For example, NTP (Network Time Protocol) is used to synchronize the time of each device. Alternatively, base station 200 and base station management apparatus 100 may be provided with a GPS (Global Positioning System) signal reception function, and the time may be synchronized based on the GPS signal.

The transmission output control section 230 controls the transmission section 250 . The transmission output control unit 230 controls the transmission unit 250 to control the transmission output (transmission power) of radio waves.

The receiving unit 240 receives radio waves transmitted from an external terminal via the antenna 260 . Transmitter 250 transmits radio waves to an external terminal via antenna 260 under the control of transmission output controller 230 .

[Data held by the base station management device]
Data held by the storage unit 130 of the base station management apparatus 100 will be described with reference to FIGS. 4, 5, and 6. FIG. FIG. 4 is a schematic diagram for explaining adjacent base station information. FIG. 5 is a schematic diagram for explaining transmission output information. FIG. 6 is a schematic diagram for explaining transmission power change time information.

FIG. 4 shows neighboring base station information for each base station. Neighboring base station information is information about base stations adjacent to a certain base station. For example, "the adjacent base stations of the first base station 200-1 are the second base station 200-2 and the third base station 200-3". This is information that associates . Neighboring base stations may be any number greater than or equal to one. Specifically, another base station having a coverage area that at least partially overlaps with an area (coverage area) in which radio waves can be received from the target base station is defined as an adjacent base station.

FIG. 5 shows transmission power information of each base station. The transmission power information includes "normal transmission power" which is the transmission power in the steady state of the base station, "minimum transmission power" which is the lower limit when the transmission power is changed, and "maximum transmission power" which is the upper limit. means. For example, in the case of the first base station 200-1, the normal transmission power is "Pn1", the minimum transmission power is "Pmin1", and the maximum transmission power is "Pmax1". Here, Pmin1, Pmin2, and Pmin3 may be different or the same. Pmax1, Pmax2, and Pmax3 may be different or the same. For example, Pmax2 and Pmax3 are set so that when the transmission power of the first base station 200-1 becomes Pmin1, the area covered when the transmission power of the first base station 200-1 is Pn1 can be covered. is set to Each transmission output may be indicated by a specific power value, or may be indicated by a level indicating the magnitude of power. When indicating the magnitude of power by level, for example, it may be indicated in three stages such as Low, Middle, and High. Alternatively, it may be represented by a five-level numerical value from 1 to 5.

FIG. 6 shows transmission power change time information. The change time interval "t" means the time (time interval until the next change in transmission power) when the base station holds the transmission power changed in stages for a certain period of time. The change time interval is also called "output hold time" or "hold time". The change completion time "T" means the time required for the base station to reach the maximum or minimum transmission power from the normal transmission power.

The base station management device 100 transmits each information shown in FIGS. 4 to 6 from the first base station 200-1 to the third base station 200-3. The first base station 200 - 1 to the third base station 200 - 3 control transmission power based on the information received from the base station management device 100 .

7 to 9, the operation of changing the transmission power when an arbitrary base station (hereinafter referred to as a base station to be restarted) is restarted and the transmission power of neighboring base stations of the base station to be restarted are changed. The operation to be performed will be described. Note that the restart target base station is sometimes called a target base station.

First, with reference to FIG. 7, the overall operation of the radio system when the restart target base station is restarted will be described. FIG. 7 is a sequence diagram showing operations of the wireless communication system. When restarting, the restart target base station performs start processing after performing stop processing. That is, the restart process is composed of two processes, stop process and start process.

As shown in FIG. 7, the restart of the base station is based on the system administrator (user) instructing the base station management apparatus to restart the base station.

The system administrator instructs the base station management device 100 to restart a specific base station by performing a predetermined operation using the input device 140 (step S11). Note that the system administrator may specify the time (date and time) of the reboot when instructing the reboot. Alternatively, a specification such as "restart immediately" or "restart in 10 minutes" may be specified. Even if the system administrator gives such an instruction that does not specify a specific time, the base station management device 100 converts the instruction from the system administrator into the restart processing start date and time. Note that the start date and time of the restart process is also called the output change start date and time, the output change start date and time when stopping, the output change start time, the output change start time when stopping, and the like. These may or may not contain date information. The date may be omitted if it does not cause confusion. Even if it contains date information, it may be called "time".

When the system administrator instructs to restart an arbitrary base station, the base station management device 100 instructs (transmits a message to) the restart target base station to restart (step S12). Specifically, the restart instruction includes information for reducing the transmission power of the restart target base station. This information is control information for controlling the transmission power of the target base station when the target base station is stopped, that is, when the target base station is stopped. information). The first stop control information includes at least information for gradually decreasing the transmission power of the target base station. At this time, the base station management apparatus 100 also transmits the transmission power change time information shown in FIG. 6 to the restart target base station. Specifically, the first stop control information includes an output change start date and time, a change time interval "t", and a change completion time "T". As will be described later, these pieces of information are used to synchronize changes in transmission power of the restart target base station with changes in transmission power of neighboring base stations. Furthermore, the transmission output information shown in FIG. 5 may be included in the first stop control information. If the transmission output information in FIG. 5 is not included in the first stop control information, each base station 200 stores this information in advance.

At the same time as step S12, the base station management device 100 instructs (transmits a message to) the adjacent base station to increase the transmission output by restarting (step S13). The instruction to raise the transmission power transmitted in step S13 is control information for controlling the transmission power of the adjacent base station when the target base station is stopped, that is, when the target base station is stopped. It is also called stop time control information (second stop control information). At this time, the base station management apparatus 100 also transmits information on the transmission power change time shown in FIG. 6 to the neighboring base stations. Specifically, the second stop time control information includes an output change start date and time, a change time interval "t", and a change completion time "T". These values are the same as the values in the first stop control information. That is, the output change start date and time in the first stop control information and the output change start date in the second stop control information are the same value, and the change time interval "t" in the first stop control information and the second stop control information are the same. The change time interval "t" in the time control information is the same value, and the change completion time "T" in the first stop time control information and the change completion time "T" in the second stop time control information are the same value. Therefore, changes in the transmission power of the target base station and changes in the transmission power of the adjacent base station can be precisely synchronized. Note that instead of the change completion time "T", the number of output changes "S" may be included in the first stop control information and the second stop control information. That is, the control information may be used to repeat the process of changing the output value to the next output value "S" times after holding the output of a constant value for the time "t". It can be said that the first stop control information and the second stop control information are “synchronization information” or “synchronization signals” for synchronizing changes (changes) in the transmission outputs of the plurality of base stations 200 . Although it is desirable to include the output change start date and time in the first stop control information and the second stop control information, it is possible to omit it. However, if omitted, the base station management device 100 determines that the difference (time difference) between the time at which the first stop control information is transmitted at step S12 and the time at which the second stop control information is transmitted at step S13 is a predetermined value. controlled to be less than Alternatively, the base station management device 100 may determine the timing of transmitting each stop time control information in consideration of the delay time of the network NW. For example, the transmission (sending) timing is determined in consideration of the delay time of the network NW so that each base station receives the stop time control information at a time difference less than a predetermined value. At this time, depending on the delay time of the network NW, there may be cases where step S13 is executed first and then step S12 is executed. By controlling the timing of transmitting the control information in this way, even if the power change start date and time are omitted, it is possible to synchronize the change of the transmission power in the plurality of base stations 200 . Therefore, even if the output change start date and time are omitted, the first stop control information and the second stop control information whose transmission timing is controlled by the base station management device 100 can be transmitted from a plurality of base stations 200. It can be said that it is "synchronization information" or "synchronization signal" for synchronizing the change (change) of the output. If the output change start date and time is omitted, the restart processing (output change processing) is immediately started in the base station that received the control information. Also, the transmission output information shown in FIG. 5 may be included in the second stop control information.

After completing the above processing, the base station management device 100 returns a response to the restart instruction to the system administrator (step S14). Specifically, the base station management apparatus 100 causes the display device 150 to display information indicating that the restart processing (transmission power change processing) has been notified to the target base station and adjacent base stations.

Upon receiving the restart instruction from the base station management device 100, the restart target base station returns a response to the base station management device 100 (step S15).

Upon receiving the instruction to increase the transmission power from the base station management device 100, the adjacent base station returns a response to the base station management device 100 (step S16).

Note that the base station management apparatus 100 may execute the process of step S14 after steps S15 and S16. Alternatively, the base station management apparatus 100 may cause the display device 150 to display information indicating that a response has been received from each base station after steps S15 and S16.

8 and 9, the change over time in the transmission power of the base station to be restarted and the adjacent base station in each stage will be described. 8 and 9, for both the base station to be restarted and the adjacent base station, the maximum transmission power is Pmax, the normal transmission power is Pn, the minimum transmission power is Pmin, the change time interval is t, and the change completion time is T. Illustrated. Assuming that the number of times the transmission output changes from time 0 to T (the number of output changes) is S, S can be expressed as T/t.

With reference to FIG. 8, the change in transmission output over time from when the restart target base station receives a restart instruction to when it restarts will be described. FIG. 8 is a schematic diagram for explaining temporal changes in the transmission output when the restart target base station performs the stop processing. In FIG. 8, the output change start date and time of the restart target base station or the time when the restart instruction is received from the base station management apparatus 100 is indicated as "0". The output change start date and time or the time at which the base station 200 receives a restart instruction from the base station management apparatus 100 may be collectively referred to as the process start time.

The transmission power immediately before the power change start date and time of the restart target base station or the restart instruction is received is the normal transmission power Pn. Upon receiving the restart instruction from the base station management apparatus 100, the restart target base station reduces the transmission power by (Pn-Pmin)/S and holds the transmission power for the change time interval t.

After the change time interval t has passed, the base station to be restarted has its transmission power reduced to the minimum transmission power Pmin
If not, the transmit power is further reduced by (Pn-Pmin)/S and held for the modified time interval t. This operation is repeated until the transmission power reaches the minimum transmission power Pmin.

The base station to be restarted restarts (stops and starts) after the change time interval t has passed with the transmission power set to the minimum transmission power Pmin. Note that Pmin may be set to "0".

Using FIG. 9, the change in time from when the adjacent base station receives an instruction to raise the transmission power until the transmission power reaches the maximum transmission power Pmax will be described. FIG. 9 is a schematic diagram for explaining temporal changes in transmission power until the transmission power of an adjacent base station reaches the maximum transmission power Pmax. In FIG. 9 , the power change start date and time or the time at which the adjacent base station receives an instruction to increase the transmission power from the base station management apparatus 100 is shown as 0. In FIG.

The transmission power up to immediately before the start of processing is Pn, which is the normal transmission power. Upon receiving the instruction to raise the transmission power, the adjacent base station raises the transmission power by (Pmax-Pn)/S and holds the transmission power for the change time interval t.

If the transmission power of the adjacent base station does not reach the maximum transmission power Pmax after the change time interval t has elapsed, the neighboring base station further raises the transmission power by (Pmax-Pn)/S and increases the transmission power by the change time interval t. hold for This operation is repeated until the transmission power reaches the maximum transmission power Pmax.

When the transmission power reaches the maximum transmission power Pmax, the adjacent base station ends the process of increasing the transmission power. In the adjacent base station, the transmission power is maintained at the maximum transmission power Pmax.

Note that the base station management apparatus 100 uses control data specifying a gradual decrease in the transmission power of the restart target base station shown in FIG. 8 and a gradual increase in the transmission power of the adjacent base station shown in FIG. may be transmitted to each base station in real time. For example, in FIG. 8, the control data is transmitted to the restart target base station at the timing of decreasing the transmission power by one step. At the same timing, control data for increasing the transmission power shown in FIG. 9 by one level is transmitted to each adjacent base station.

As shown in FIGS. 8 and 9, in this embodiment, control is performed to stepwise lower the transmission power of the restart target base station and stepwise increase the transmission power of the adjacent base station. By performing such control, it is possible to cause the terminals whose locations have been registered with the restart target base station to be sequentially registered with adjacent base stations. Therefore, it is possible to reduce the situation where the terminal is not registered with any base station and cannot communicate. In addition, by changing the transmission power step by step in this way, it is possible to prevent location registration of terminals from being concentrated in a short period of time in neighboring base stations. That is, it is possible to avoid concentration of load on some base stations. Furthermore, by synchronizing the process of gradually lowering the transmission power of the base station to be restarted and the process of gradually increasing the transmission power of the adjacent base station, the terminal whose location is registered with the base station to be restarted can be It is possible to appropriately sequentially perform location registration with neighboring base stations.

Next, with reference to FIGS. 10 to 12, the operation of changing the transmission power after the restart target base station is restarted and the operation of the adjacent base station changing the transmission power will be described.

First, with reference to FIG. 10, the overall operation of the radio system after the restart target base station is restarted will be described. FIG. 10 is a sequence diagram showing operations of the wireless communication system.

As shown in FIG. 10, when the restart target base station completes the restart, it notifies the base station management apparatus 100 of a startup completion notification indicating that it has been started (step S21). Note that "completion of restart" refers to a state in which the base station to be restarted can transmit radio waves.

Upon receiving the activation completion notification, the base station management device 100 calculates the output change start date and time based on the received time, and instructs the base station to be rebooted to increase the transmission output due to activation completion (step S22). ). For example, the date and time obtained by adding a predetermined time (for example, 10 seconds) to the received time is set as the output change start date and time (output change start date and time at startup). The instruction to raise the transmission power transmitted in step S22 is control information for controlling the transmission power of the target base station at the time of activation of the target base station, that is, at the time of activation of the target base station. It is also called start-up control information (first start-up control information). The first startup control information includes information for stepwise increasing the transmission power of the target base station. Specifically, the first start-up control information includes the output change start date and time calculated in step S22, the change time interval "t", and the change completion time "T". As will be described later, these pieces of information are used to synchronize changes in transmission power of the restart target base station with changes in transmission power of neighboring base stations. Furthermore, the transmission power information shown in FIG. 5 may be included in the first startup control information.

At the same time as step S22, the base station management device 100 instructs the adjacent base station to lower the transmission due to the completion of activation (step S23). Since the instruction to lower the transmission power transmitted in step S23 is control information for controlling the transmission power of the adjacent base station when the target base station is activated, that is, when the target base station is activated, the second It is also called start-up control information (second start-up control information). Specifically, the second start-up control information includes an output change start date and time, a change time interval "t", and a change completion time "T". These values are the same as the values in the first startup control information. That is, the output change start date and time in the first startup control information and the output change start date in the second startup control information are the same value, and the change time interval "t" in the first startup control information and the second startup control information are the same. The change time interval "t" in the time control information has the same value, and the change completion time "T" in the first startup control information and the change completion time "T" in the second startup control information have the same value. Therefore, changes in the transmission power of the target base station and changes in the transmission power of the adjacent base station can be precisely synchronized. Note that instead of the change completion time "T", the number of output changes "S" may be included in the first start-up control information and the second start-up control information. That is, the control information may be used to repeat the process of changing the output value to the next output value "S" times after holding the output of a constant value for the time "t". It can be said that the first startup control information and the second startup control information are “synchronization information” or “synchronization signals” for synchronizing changes (changes) in the transmission outputs of the plurality of base stations 200 . It is desirable that the first startup control information and the second startup control information include the output change start date and time, but it is possible to omit it. However, if omitted, the base station management device 100 sets the difference (time difference) between the time at which the first startup control information is transmitted at step S22 and the time at which the second startup control information is transmitted at step S23 to a predetermined value. controlled to be less than Alternatively, the base station management apparatus 100 may determine the timing of transmitting each startup control information in consideration of the delay time of the network NW. For example, the transmission (sending) timing is determined in consideration of the delay time of the network NW so that each base station receives the stop time control information at a time difference less than a predetermined value. At this time, depending on the delay time of the network NW, there may be cases where step S23 is executed first and then step S22 is executed. By controlling the timing of transmitting the control information in this way, even if the power change start date and time are omitted, it is possible to synchronize the change of the transmission power in the plurality of base stations 200 . Therefore, even if the output change start date and time are omitted, the first start-up control information and the second start-up control information whose transmission timing is controlled by the base station management device 100 can be transmitted from a plurality of base stations 200. It can be said that it is "synchronization information" or "synchronization signal" for synchronizing the change (change) of the output. If the output change start date and time is omitted, the restart processing (output change processing) is immediately started in the base station that received the control information. Also, the base station management apparatus 100 may transmit the transmission power information shown in FIG. 5 to the adjacent base station.

Note that the first start-up control information is "first control information", the second start-up control information is "second control information", the first stop-time control information is "third control information", and the second stop-time control information is is sometimes called "fourth control information". In the sequence shown in FIG. 7, the first startup control information may be included in the first shutdown control information transmitted from the base station management apparatus 100 to the restart target base station. In other words, not only the change pattern of the transmission power at the time of shutdown in the restart target base station but also the change pattern of the transmission power at the time of start-up may be included. Also, the second start-up control information may be included in the second stop-time control information transmitted from the base station management device 100 to the adjacent base station. That is, even if the change pattern of the transmission power of the neighboring base station when the restart target base station is started is included, not only the change pattern of the transmission power of the neighboring base station when the restart target base station is stopped. good.

Upon receiving the transmission power increase instruction from the base station management device 100, the restart target base station returns a response to the base station management device 100 (step S24).

Upon receiving the instruction to lower the transmission power from the base station management device 100, the neighboring base station returns a response to the base station management device 100 (step S25).

In the example shown in FIG. 10, after the base station management apparatus 100 receives the startup completion notification from the restart target base station, it transmits information for changing the transmission power to each base station. , another method may be used. For example, in the sequence shown in FIG. 7, the transmission power change pattern after activation may be included in the restart instruction information transmitted from the base station management apparatus 100 to the base station to be restarted. That is, when the restart target base station executes the restart processing (stop processing), it may notify the change pattern of the transmission output after the restart. The restart information may include information on the time (date and time) at which the transmission power is changed, in addition to the change pattern of the transmission power after startup. In other words, the base station to be restarted may start transmission power control at a predetermined timing according to the progress of its own startup processing, or may start transmission power control at a time specified by the base station management apparatus 100. may start.

11 and 12, changes over time in the transmission output of the restart target base station and the adjacent base stations in the post-restart stage will be described. 11 and 12, for both the base station to be restarted and the adjacent base station, the maximum transmission power is Pmax, the normal transmission power is Pn, the minimum transmission power is Pmin, the change time interval is t, and the change completion time is T. Illustrated. Assuming that the number of times the transmission output changes from time 0 to T (the number of output changes) is S, S can be expressed as T/t.

Using FIG. 11, the change in time from when the restart target base station receives an instruction to withdraw transmission until the transmission power reaches Pn, which is the normal transmission power, will be described. FIG. 11 is a schematic diagram for explaining a change in transmission power over time until the transmission power of the restart target base station reaches the normal transmission power Pn. In FIG. 11, the power change start date and time of the base station to be restarted or the time when an instruction to raise the transmission power is received from the base station management apparatus 100 is shown as 0. In FIG.

The transmission power immediately before the power change start date and time of the restart target base station or the instruction to increase the transmission power of the restart target base station is received is the minimum transmission power Pmin. Upon receiving an instruction to raise the transmission power from the base station management apparatus 100, the restart target base station maintains the transmission power at Pmin for the change time interval t.

After the change time interval t has elapsed, the base station to be restarted increases its transmission power by (Pn-Pmin)/S, and if its transmission power does not reach the normal transmission power Pn, it changes its transmission power. Hold for time interval t. The restart target base station repeats this operation until it reaches the normal transmission power Pn.

After the change time interval t has elapsed, the base station to be restarted raises the transmission power by (Pn-Pmin)/S, and when the transmission power reaches the normal transmission power Pn, the transmission power raising process ends. do. As a result, the transmission power of the restart target base station is maintained at Pn, which is the normal transmission power.

Using FIG. 12, the change in time from when the adjacent base station receives an instruction to lower the transmission power until the transmission power reaches the normal transmission power Pn will be described. FIG. 12 is a schematic diagram for explaining temporal changes in transmission power until the transmission power of an adjacent base station reaches the normal transmission power Pn. In FIG. 12 , the date and time when the power change of the adjacent base station is started or the time when an instruction to lower the transmission power is received from the base station management apparatus 100 is shown as 0. In FIG.

The transmission output until the output change start date and time of the adjacent base station or immediately before receiving the instruction to reduce the transmission output of the adjacent base station is the maximum transmission output Pmax. Upon receiving the instruction to lower the transmission power, the neighboring base station maintains the transmission power in the state of Pmax for the change time interval t.

After the change time interval t has elapsed, the neighboring base station reduces its transmission power by (Pmax-Pn)/S, and if its transmission power has not reached the normal transmission power Pn, it reduces its transmission power by the change time interval. Hold for t. This operation is repeated until the transmission power reaches the normal transmission power Pn.

After the change time interval t has passed, the adjacent base station reduces the transmission power by (Pmax-Pn)/S, and if the transmission power reaches the normal transmission power Pn, the process of reducing the transmission power ends. As a result, the transmission power of the adjacent base station is maintained at the normal transmission power Pn.

Control data designating a gradual increase in the transmission power of the restart target base station shown in FIG. 11 and a gradual decrease in the transmission power of the adjacent base station shown in FIG. 12 is transmitted to each base station in real time. may For example, in FIG. 11, the control data is transmitted to the restart target base station at the timing of increasing the transmission output by one step. Also, at the same timing, control data for decreasing the transmission power shown in FIG. 12 by one level is transmitted to each adjacent base station.

As shown in FIGS. 11 and 12, the transmission power of the base station to be restarted is increased stepwise, and the transmission power of the adjacent base station is decreased stepwise. By performing such control, terminals whose locations have been registered with adjacent base stations can be sequentially registered with the restart target base station. Therefore, it is possible to reduce the situation where the terminal is not registered with any base station and cannot communicate. In addition, by changing the transmission power step by step in this way, it is possible to prevent location registration of terminals from being concentrated in a short period of time in the restart target base station. Furthermore, by synchronizing the process of gradually increasing the transmission power of the base station to be restarted and the process of gradually decreasing the transmission power of the adjacent base station, terminals whose location is registered with the adjacent base station can be more appropriately handled. Location registration can be sequentially performed on the base stations to be restarted. That is, it is possible to avoid concentration of load on some base stations.

The change in the transmission output at the time of restarting and after the restarting described above is merely an example, and may be changed in other patterns. For example, it may be changed smoothly (continuously) instead of stepwise.

The operation of restarting the base station and changing each coverage area step by step will be described with reference to FIGS. 13A to 13D. FIGS. 13A to 13D are schematic diagrams for explaining the operation in which each cover area changes step by step. FIGS. 13A to 13D are described assuming that the first base station 200-1 is the restart target base station. In this case, the second base station 200-2 and the third base station 200-3 are neighboring base stations.

FIG. 13A shows the coverage area immediately before the first base station 200-1 restarts. In this case, each of the first base station 200-1 to the third base station 200-3 outputs radio waves of normal transmission power. In this case, the coverage area of the first base station 200-1 is the first coverage area 300-1. The communicable area of the second base station 200-2 is the second coverage area 300-2. The communicable area of the third base station 200-3 is the third coverage area 300-3. In FIG. 13A, first terminal 10-1 to sixth terminal 10-6 are located within first coverage area 300-1. In this case, first terminal 10-1 to sixth terminal 10-6 are assumed to be communicably connected to first base station 200-1. When restarting the first base station 200-1, each coverage area changes in the order of FIGS. 13A, 13B, 13C, and 13D.

FIG. 13B shows a state in which the coverage area is changed by one step from FIG. 13A. The first coverage area 300A-1 is narrower than the first coverage area 300-1 shown in FIG. 13A. The second coverage area 300A-2 and the third coverage area 300A-3 are wider than the second coverage area 300-2 and the third coverage area 300-3 shown in FIG. 13A. In FIG. 13B, third terminal 10-3 and fourth terminal 10-4 are out of first coverage area 300A-1. The third terminal 10-3 and the fourth terminal 10-4 are located within the second coverage area 300A-2 and the third coverage area 300A-3. In this case, the third terminal 10-3 and the fourth terminal 10-4 are connected to the second base station 200-2 or the third base station 200-3.

FIG. 13C shows a state in which the coverage area is changed by one step from FIG. 13B. The first coverage area 300B-1 is narrower than the first coverage area 300A-1 illustrated in FIG. 13B. The second coverage area 300B-2 and the third coverage area 300B-3 are wider than the second coverage area 300A-2 and the third coverage area 300A-3 illustrated in FIG. 13B. In FIG. 13C, in addition to the third terminal 10-3 and the fourth terminal 10-4, the first terminal 10-1 and the sixth terminal 10-6 are out of the first coverage area 300B-1. The first terminal 10-1 is located within the second coverage area 300B-2 and connects to the second base station 200-2. The sixth terminal 10-6 is located within the third coverage area 300B-3 and connects to the third base station 200-3.

FIG. 13D shows a state in which the coverage area is changed by one step from FIG. 13C. The first coverage area 300C-1 is narrower than the first coverage area 300B-1 shown in FIG. 13C. The first coverage area 300C-1 is the coverage area when the first base station 200-1 outputs radio waves with the minimum transmission power Pmin1. The second coverage area 300C-2 and the third coverage area 300C-3 are wider than the second coverage area 300B-2 and the third coverage area 300B-3 illustrated in FIG. 13C. The second coverage area 300C-2 and the third coverage area 300C-3 are coverage areas when the second base station 200-2 and the third base station 200-3 respectively output radio waves at the maximum transmission outputs Pmax2 and Pmax3. is. In FIG. 13D, the second terminal 10-2 and the fifth terminal 10-5 are further out of the first coverage area 300C-1. The second terminal 10-2 and the fifth terminal 10-5 are located within the second coverage area 300C-2 and the third coverage area 300C-3. In this case, the second terminal 10-2 and the fifth terminal 10-5 are connected to the second base station 200-2 or the third base station 200-3. After that, the first base station 200-1 restarts.

14 to 16, the operation of each part of the base station management device, the restart target base station, and the adjacent base station when the restart target base station is restarted will be described. FIG. 14 is a flow chart showing the processing flow of each part of the base station management device when the restart target base station is restarted. FIG. 15 is a flowchart showing the flow of processing of each part of the restart target base station when the restart target base station is restarted. FIG. 16 is a flow chart showing the processing flow of each part of the adjacent base station when the restart target base station is restarted.

As shown in FIG. 14, in the base station management apparatus 100, first, the communication unit 110 inputs the restart instruction received from the input device 140 to the processing unit 120 (step S101).

Next, the processing unit 120 acquires neighboring base station information shown in FIG. 4 from the storage unit 130 (step S102). By acquiring adjacent base station information, the processing unit 120 recognizes that the adjacent base stations of the first base station 200-1 are the second base station 200-2 and the third base station 200-3.

Next, the processing unit 120 acquires the transmission output information shown in FIG. 5 from the storage unit 130 (step S103). In step S103, the processing unit 120 obtains the transmission output information of the first base station 200-1, which is the base station to be restarted, and the second base station 200-2 and the third base station 200-3, which are adjacent base stations. get.

Next, the processing unit 120 acquires transmission output change time information shown in FIG. 6 from the storage unit 130 (step S104).

Next, the processing unit 120 instructs the first base station 200-1, which is the base station to be restarted, to restart (first stop control information) via the communication unit 110 together with each information acquired from the storage unit 130. (step S105).

Next, the processing unit 120, together with the information acquired from the storage unit 130, transmits the transmission power to the adjacent base stations, the second base station 200-2 and the third base station 200-3, via the communication unit 110. A pull-up (second stop time control information) is notified (step S106). The base station management device 100 then terminates the processing of FIG.

Next, the processing of each part of the first base station 200-1, which is the base station to be restarted, will be described with reference to FIG. The processing shown in the flowchart of FIG. 15 is started at the timing when the change start date and time included in the first stop control information arrives or at the timing when the first base station 200-1 receives the first stop control information.

First, the communication unit 210 inputs to the processing unit 220 the restart instruction (first stop time control information) received from the base station management device 100 (step S201).

Next, the processing unit 220 returns a response to the restart instruction to the base station management device 100 via the communication unit 210 (step S202).

Next, the processing unit 220 reduces the transmission power by (Pn1-Pmin1)/S via the transmission power control unit 230, and starts the timer for the change time interval t (step S203).

Next, after the change time interval t has elapsed, the processing unit 220 determines whether or not the transmission power is the minimum transmission power (step S204). If it is not the minimum transmission output (No in step S204), the processing unit 220 proceeds to step S203. On the other hand, if it is the minimum transmission output (Yes in step S204), the processing unit 220 proceeds to step S205.

Next, the processing unit 220 restarts the first base station 200-1 (step S205). Then, the first base station 200-1 ends the processing of FIG. It should be noted that this restarting is a process of temporarily stopping at least some of the computers and the like that constitute the first base station 200-1 and then starting them.

In parallel with the processing of FIG. 15, the second base station 200-2 and the third base station 200-3 execute the processing of FIG. The processing shown in the flowchart of FIG. 16 is performed at the timing when the change start date and time included in the second stop control information arrives, or when the second base station 200-2 and the third base station 200-3 receive the second stop control information. It starts when it is received. Since the second base station 200-2 and the third base station 200-3 perform similar processing, the processing of the second base station 200-2 will be described below, and the processing of the third base station 200-3 will be described. are omitted.

First, the communication unit 210 inputs to the processing unit 220 an instruction (second stop time control information) received from the base station management device 100 to stop transmission (step S301).

Next, the processing unit 220 returns a response to the suspension of transmission to the base station management device 100 via the communication unit 210 (step S302).

Next, the processing unit 220 increases the transmission power by (Pmax2-Pn2)/S via the transmission power control unit 230, and starts the timer for the change time interval t (step S303).

Next, after the change time interval t has elapsed, the processing unit 220 determines whether or not the transmission power is the maximum transmission power (step S304). If it is not the maximum transmission output (No in step S304), the processing unit 220 proceeds to step S303. On the other hand, if it is the maximum transmission output (Yes in step S304), the processing unit 220 terminates the processing of FIG.

As described above, the transmission power of each base station 200 to be processed is synchronized and changed step by step, so that from the first base station 200-1 to the second base station 200-2 or the third base station 200- It is possible to avoid congestion due to the terminals moving to 3 all at once. Also, by increasing the transmission power of the second base station 200-2 and the third base station 200-3, it is possible to avoid each terminal being out of service area due to the restart of the first base station 200-1. can.

Next, with reference to FIG. 13A to FIG. 13D, processing until the restart of the first base station 200-1 is completed and the transmission power of each base station returns to the normal transmission power will be described.

After the restart of the first base station 200-1 is completed, the transmission power of each base station changes in the order of FIGS. 13D, 13C, 13B, and 13A until the normal transmission power. In other words, the change is the opposite of when the first base station 200-1 is restarted. Note that the connection relationship between each terminal and each base station in FIGS. 13A to 13D is the same as the situation when the first base station 200-1 is restarted, so description thereof will be omitted.

Using FIGS. 17 to 19, after the restart target base station is restarted, the base station management apparatus, the restart target base station, and the neighboring bases until the transmission power of each base station returns to the normal transmission power. The operation of each part of the station will be explained. FIG. 17 is a flow chart showing the processing flow of each part of the base station management device until the transmission power of each base station returns to the normal transmission power. FIG. 18 is a flow chart showing the processing flow of each part of the restart target base station until the transmission power of each base station returns to the normal transmission power. FIG. 19 is a flow chart showing the processing flow of each part of the adjacent base station until the transmission power of each base station returns to the normal transmission power.

As shown in FIG. 17, in the base station management device 100, first, the communication unit 110 inputs the activation completion notification received from the input device 140 to the processing unit 120 (step S401).

Next, the processing unit 120 acquires neighboring base station information shown in FIG. 4 from the storage unit 130 (step S402).

Next, the processing unit 120 acquires the transmission output information shown in FIG. 5 from the storage unit 130 (step S403).

Next, the processing unit 120 acquires transmission output change time information shown in FIG. 6 from the storage unit 130 (step S104).

Next, the processing unit 120 raises the transmission power (first startup control information ) is notified (step S405).

Next, the processing unit 120, together with the information acquired from the storage unit 130, transmits the transmission power to the adjacent base stations, the second base station 200-2 and the third base station 200-3, via the communication unit 110. A lowering (second start-up control information) is instructed (step S406). The base station management device 100 then terminates the processing of FIG.

Next, the processing of each part of the first base station 200-1, which is the base station to be restarted, will be described with reference to FIG. The process shown in the flowchart of FIG. 18 is started at the timing when the change start date and time included in the first startup control information arrives or at the timing when the first base station 200-1 receives the first startup control information.

First, the communication unit 210 inputs, to the processing unit 220, an instruction to increase the transmission power (first startup control information) received from the base station management device 100 (step S501).

Next, the processing unit 220 returns a response to the instruction to increase the transmission power to the base station management device 100 via the communication unit 210 (step S502).

Next, the processing unit 220 maintains the transmission power at Pmin1 via the transmission power control unit 230, and starts the timer for the change time interval t (step S503).

Next, after the change time interval t has elapsed, the processing unit 220 raises the transmission power by (Pn1-Pmin1)/S via the transmission power control unit 230 (step S504).

Next, after the change time interval t has elapsed, the processing unit 220 determines whether or not the transmission output is the normal transmission output (step S505). If it is not normal transmission output (No in step S505), the processing unit 220 proceeds to step S504. On the other hand, if it is the normal transmission output (Yes in step S505), the processing unit 220 ends the processing in FIG.

In parallel with the processing of FIG. 18, the second base station 200-2 and the third base station 200-3 execute the processing of FIG. The processing shown in the flowchart of FIG. 19 is performed at the timing when the change start date and time included in the second startup control information arrives, or when the second base station 200-2 and the third base station 200-3 receive the second startup control information. It starts when it is received. Since the second base station 200-2 and the third base station 200-3 perform similar processing, the processing of the second base station 200-2 will be described below, and the processing of the third base station 200-3 will be described. are omitted.

First, the communication unit 210 inputs to the processing unit 220 the transmission reduction instruction (second start-up control information) received from the base station management apparatus 100 (step S601).

Next, the processing unit 220 returns a response to the transmission reduction to the base station management device 100 via the communication unit 210 (step S602).

Next, the processing unit 220 maintains the transmission power at Pmax2 via the transmission power control unit 230, and starts the timer for the change time interval t (step S603).

After the change time interval t has elapsed, the processing unit 220 reduces the transmission power by (Pmax2-Pn2)/S via the transmission power control unit 230 (step S604).

Next, after the change time interval t has elapsed, the processing unit 220 determines whether or not the transmission output is the normal transmission output (step S605). If it is not normal transmission output (No in step S605), the processing unit 220 proceeds to step S604. On the other hand, if it is the normal transmission output (Yes in step S605), the processing unit 220 ends the processing in FIG. The second base station 200-2 then terminates the processing of FIG.

As described above, according to the present embodiment, by changing the transmission power in stages, it is possible to avoid congestion due to the simultaneous movement of terminals to the first base station 200-1.

In this embodiment, transmission power control when the restart target base station is stopped as shown in FIGS. 8 and 9 and restart target base station as shown in FIGS. Although both the transmission output control is performed when the transmission is performed, only one of them may be performed. For example, when a certain base station is to be stopped rather than restarted, transmission power control when the base station to be restarted is started is omitted. Also, when starting up a base station that has not been started up until now, the transmission power control when the base station to be restarted is stopped is omitted.

In this embodiment, the transmission power control of the restart target base station and the transmission power control of the adjacent base station are performed simultaneously, but the transmission power control of the adjacent base station may be omitted. That is, the transmission power of neighboring base stations may be constant. For example, when a certain base station is activated, the transmission power of that base station is varied as shown in FIG. 11, but the transmission power of adjacent base stations may be constant. Controlling the transmission power of the adjacent base station enables the terminal to smoothly transition from the adjacent base station to the active base station. It is possible to obtain the effect of preventing

[Second embodiment]
Next, the wireless communication system 1 according to the second embodiment will be described. The configuration of the radio communication system according to the second embodiment is the same as that of the first embodiment.

In the second embodiment, the base station management apparatus 100 determines the power transmission output change pattern of the restart target base station and adjacent base stations according to the number of terminals registered in the restart target base station.

Specifically, in the second embodiment, the base station management apparatus 100 increases the change completion time T as the number of terminals registered in the base station to be restarted increases before performing the restart process. reduce the amount of change in the transmission output per transmission. That is, as the number of terminals registered in the restart target base station increases in the past (past point in time), the transmission power is changed little by little. As the number of terminals, the number of terminals registered in the base station to be activated at the point immediately before the restart process (most recent) may be used, or the number of terminals registered in the base station to be activated for a certain period of time in the past (for example, the number of terminals before the restart process is performed). 1 hour), a representative value (average value, median value, etc.) of the number of terminals registered in the activation target base station may be used.

As described above, the number of times the transmission output is changed from time 0 to time T (the number of output changes) S can be expressed as S=T/t. Also, since the amount of change in transmission power per change is determined as (Pn-Pmin)/S or (Pmax-Pn)/S, for example, the larger the value of S, the more the change in transmission power. quantity becomes smaller.

For example, if the number of terminals registered in the restart target base station is less than the threshold θ (for example, 20) before restart processing, T=T1. Moreover, when it is equal to or greater than the threshold value θ, T=T2. Here, T1 and T2 satisfy the relationship of T1<T2, and T2 is a larger value than T1. Also, here, the same value of t is used regardless of the number of terminals in the restarting base station.

Differences in output change patterns (output change patterns) due to differences in the number of terminals will be described with reference to FIGS. 20A and 20B. FIGS. 20A and 20B show examples of output change patterns when stopping a restart target base station.

FIG. 20A shows output change patterns when the number of registered terminals in the base station to be restarted is small (below the threshold), and FIG. ) shows the output change pattern. As shown in FIGS. 20A and 20B, the number of output changes is four in FIG. 20A, and eight in FIG. 20B. Also, the amount of change in transmission output is smaller in FIG. 20B than in FIG. 20A.

Note that the change completion time T may be adjusted more finely using two or more types of thresholds. For example, using two types of threshold values θ1 and θ2 (θ1<θ2), T=T1 when the number of terminals in the base station to be restarted is less than θ1, and T=T1 when θ1 or more and less than θ2 , T=T22, and if .theta.2 or more, T=T3. Here, T1, T2, and T3 satisfy the relationship of T1<T2<T3.

As described above, the amount of change in the transmission power of the restarting base station and neighboring base stations may be determined according to the number of terminals registered with the restarting base station. By performing such processing, it is possible to reduce the possibility that an excessive load is applied to the adjacent base station when stopping the restart target base station. In addition, when the restart target base station is activated, it is possible to reduce the possibility that an excessive load is applied to the restart target base station.

Also, in this embodiment, the change completion time and the change time interval t may be set according to the number of terminals registered in the restart target base station. For example, when the number of terminals registered in the restart target base station is less than the threshold θ, T=T1 and t=t1 are used. Then, when the number of terminals is equal to or greater than the threshold θ, T=4×T1 and t=2×t1. An example of the power change pattern of the target base station when performing such processing is shown in FIGS. 21A and 21B.

FIG. 21A is a schematic diagram showing an output change pattern when the number of registered terminals in the restart target base station is small (less than the threshold). FIG. 21B is a schematic diagram showing an output change pattern when the number of registered terminals in the restart target base station is large (threshold or more). The change time interval of the output change pattern shown in FIG. 21A is t1, and the change completion time is T1. The change time interval of the output change pattern shown in FIG. 21B is 2×t1, and the change completion time is 4×T1.

With this setting, when the number of terminals is large (threshold θ or more), the number of output changes S is doubled compared to when the number of terminals is small (less than the threshold). The amount of change per time is also small. Furthermore, since the same output value lasts twice as long, it is possible to further reduce the possibility that the base station to be restarted and the adjacent base station will be overloaded. In other words, according to the number of terminals registered in the restart target base station, by setting the first stop control information and the second stop control information and changing the transmission output change pattern defined by these, It is possible to further reduce the possibility that the base station to be restarted and the adjacent base station will be overloaded. Even if the number of terminals registered in the base station 200 is reduced by lowering the transmission power, such processing is effective because the registration change processing occurs in the base station 200 . The examples of the change completion time T and the change time interval t described above are merely examples, and do not limit the present invention. For example, other settings such as T=3×T1 and t=2×t1 may be used when the threshold value θ is exceeded. However, it is desirable that the number of output changes when the number of terminals is large should not be less than the number of output changes when the number of terminals is small.

It should be noted that processing similar to the above-described processing may also be performed in the processing when the restart target base station is activated. For example, according to the number of terminals registered in the restart target base station in the past, the same processing as the processing described using FIGS. 20A, 20B, 21A, and 21B is performed, Modifications may be made to the output modification patterns shown. That is, the base station management apparatus 100 sets the first startup control information and the second startup control information according to the number of terminals registered in the restart target base station, and sets the transmission output defined by the first control information and the second startup control information. You can change the change pattern. Such processing can further reduce the possibility that the restart target base station and the adjacent base station will be overloaded.

[Third Embodiment]
Next, the radio communication system 1 according to the third embodiment will be described. The configuration of the radio communication system according to the third embodiment is the same as that of the first embodiment.

In the third embodiment, the timing for changing the transmission power of the restart target base station and the adjacent base station may be determined while monitoring the position registration request of the terminal. The location registration request is monitored, for example, by the base station that increases the transmission power. That is, the timing of changing the transmission power of the restart target base station and the adjacent base station may be determined according to the number of registrations of the restart target base station.

Specifically, the base station management apparatus 100 gradually lowers the transmission power for restarting the base station to be restarted, that is, when the adjacent base station raises the transmission power step by step. Then, the timing for changing the transmission power is determined based on the number of location registration requests per unit time from neighboring base stations. If the number of location registration requests per unit time in the adjacent base station is less than a predetermined value (threshold value), the base station management device 100 increases the transmission power of the adjacent base station, You can reduce the transmission power of When the number of location registration requests per unit time in adjacent base stations is equal to or greater than a predetermined value, the base station management apparatus 100 maintains the same state without changing the transmission power of both the restart target base station and the adjacent base stations. .

Processing of the base station management apparatus when the restart target base station is stopped will be described with reference to FIG. FIG. 22 is a flow chart showing an example of the processing flow of the base station management device.

First, the processing unit 120 acquires the number of location registration requests per unit time from each neighboring base station via the communication unit 110 (step S701).

Next, the processing unit 120 determines whether or not the number of location registration requests per unit time is less than a predetermined value (threshold value) in all neighboring base stations (step S702). If it is determined that the number of location registration requests is less than the predetermined value (threshold value) (Yes in step S702), the processing unit 120 proceeds to step S703. On the other hand, if it is determined that the number of location registration requests is not less than the predetermined value (threshold value) (No in step S702), the processing unit 120 proceeds to step S704.

At step 703, the processing unit 120 transmits an output change instruction (output change message) to each base station (step S703). That is, the processing unit 120 transmits a message to lower the transmission power by one level to the restart target base station, and a message to raise the transmission power by one level to the adjacent base station. Alternatively, the processing unit 120 may send a message directly specifying the transmission power value to be used to each base station. In this embodiment, in order to change the transmission power of the base station 200 by one step, the base station management apparatus 100 transmits a message to the base station 200 each time.

Next, the processing unit 120 determines whether or not the restart target base station has stopped (step S704). Specifically, the processing unit 120 transmits a message to the base station management apparatus 100 immediately before the restart target base station stops, and determines whether or not the message has been received. . Alternatively, the processing unit 120 may transmit a message from the base station management apparatus 100 to the base station to be restarted to confirm whether or not the base station has stopped, and determine whether or not there is a response to the message. If it is determined that the restart target base station has stopped (Yes in step S704), the processing unit 120 terminates the processing of FIG. On the other hand, if it is not determined that the restart target base station has stopped (No in step S704), the processing unit 120 proceeds to step S705.

Next, the processing unit 120 waits for a predetermined time (for example, 10 seconds) (step S705). Then, the processing unit 120 proceeds to step S701 and repeats the above-described processing.

Similarly, when the base station management apparatus 100 gradually increases the transmission power after the restarting base station is restarted, the number of location registration requests per unit time at the restarting base station is a predetermined value ( threshold), the transmission power of the restarting base station may be increased and the transmission power of the neighboring base station may be decreased.

Processing of the base station management apparatus after restarting the base station to be restarted will be described with reference to FIG. FIG. 23 is a flow chart showing an example of the processing flow of the base station management device. The processing in FIG. 23 is triggered by the reception of a predetermined message from the base station to be restarted by the base station management device.

The processing unit 120 acquires the number of location registration requests per unit time from the restart target base station via the communication unit 110 (step S801).

Next, the processing unit 120 determines whether or not the number of location registration requests per unit time is less than a predetermined value (threshold value) in the restart target base station (step S802). If it is determined that the number of location registration requests is less than the predetermined value (threshold value) (Yes in step S802), the processing unit 120 proceeds to step S803. On the other hand, if it is determined that the number of location registration requests is not less than the predetermined value (threshold value) (No in step S802), the processing unit 120 proceeds to step S804.

In step S803, processing unit 120 transmits an output change instruction (output change message) to each base station (step S803). That is, the processing unit 120 transmits a message to increase the transmission power by one level to the restart target base station, and transmits a message to decrease the transmission power by one level to the adjacent base station. Alternatively, the processing unit 120 may transmit a message directly designating the transmission power value to be used to each base station.

Next, the processing unit 120 determines whether or not the restart target base station is in the normal state (normal output state) (step S804). That is, the processing unit 120 determines whether or not the power change processing of the restart target base station has been completed. Specifically, when the output change processing of the restart target base station is completed, the processing unit 120 transmits a message to that effect to the base station management device, and determines whether or not the message has been received. determine whether If it is determined that the restart target base station is in the normal state (Yes in step S804), the processing unit 120 ends the processing of FIG. On the other hand, if it is determined that the restart target base station is not in the normal state (No in step S804), the processing unit 120 proceeds to step S805.

Next, the processing unit 120 waits for a predetermined time (for example, 10 seconds) (step S805). Then, the processing unit 120 advances to step S801 and repeats the above-described processing.

By executing the above-described processing, the base station management apparatus 100 reduces the possibility that the restart target base station and the neighboring base stations will be overloaded, and at the same time, the restart target base station can be restarted in the minimum necessary time. Can perform shutdown and startup operations.

In the above description, the base station management apparatus 100 acquires the number of location registration requests per unit time of each base station and performs determination processing, but another method may be used. For example, in the process of stopping the restart target base station, each neighboring base station may determine whether or not the number of location registration requests per unit time is less than a predetermined value. In this case, if it is less than the predetermined value, it is determined that the transmission power of the own base station can be increased, and a message to that effect (output increase possible message) is transmitted to the base station management apparatus 100 . When the base station management device 100 receives power increase possible messages from all adjacent base stations, it transmits a power change instruction (power change message) to each base station. That is, the base station management apparatus 100 transmits a message to lower the transmission power by one level to the base station to be restarted, and a message to raise the transmission power by one level to the adjacent base station.

Similarly, in the process of increasing the output of the restart target base station, the restart target base station may determine whether or not the number of location registration requests per unit time is less than a predetermined value. In this case, if the number of location registration requests is less than a predetermined value, it is determined that the transmission power of the own base station can be increased, and a message to that effect (output increase possible message) is sent to the base station management device 100. Send. When the base station management apparatus 100 receives a power increase possible message from a restart target base station, it transmits a power change instruction (power change message) to each base station. That is, the base station management apparatus 100 transmits a message to increase the transmission power by one level to the base station to be restarted, and transmits a message to decrease the transmission power by one level to the adjacent base station.

[Fourth embodiment]
Next, the wireless communication system 1 according to the fourth embodiment will be described. The configuration of the wireless communication system according to the fourth embodiment is the same as that of the first embodiment.

In the fourth embodiment, location information of terminals registered in the restart target base station may be used to select adjacent base stations whose transmission power is to be changed.

Specifically, the base station management apparatus 100 provides information (latitude, longitude, etc. of the coverage area) regarding the maximum coverage area of each base station (the coverage area when the output is set to the maximum value), and information registered in each base station. The location information (latitude, longitude, etc.) of the acquired terminal is stored in the storage unit 130 . Then, when the restart target base station is restarted, the base station management apparatus 100 can cover the terminal registered in the restart target base station (the terminal can be placed in range instead of the target base station). Only stations may be subject to transmission power control.

A method of selecting an adjacent base station using terminal location information will be described with reference to FIG. FIG. 24 is a schematic diagram for explaining an example of a method of selecting adjacent base stations using terminal location information.

In FIG. 24, a first base station 200-1 is a restart target base station, and a second base station 200-2 and a third base station 200-3 are adjacent base stations. Assume that first terminal 10-1, second terminal 10-2, and third terminal 10-3 are registered in first base station 200-1. Before the restart processing of the first base station 200-1 is performed, the three terminals from the first terminal 10-1 to the third terminal 10-3 are in the maximum second coverage area of the second base station 200-2. 300C-2 is shown. In other words, there are 3 There are terminals. On the other hand, there is no terminal in area 400-2 where first coverage area 300-1 of first base station 200-1 and maximum coverage area 300C-3 of third base station 200-3 overlap. In such a state, even if the transmission power of the third base station 200-3 is maximized, the terminal registered with the first base station 200-1 will not be registered with the third base station 200-3. Therefore, changing the transmission power of the third base station 200-3 is useless. Therefore, the third base station 200-3 is excluded from the target of changing the transmission power, and only the second base station 200-2 is the target of changing the transmission power.

Further, in the fourth embodiment, the transmission power change pattern may be changed using location information of terminals registered in the restart target base station.

Specifically, when the restart target base station lowers the transmission power, if the number of terminals existing in the coverage area of the restart target base station becomes zero, the transmission may be stopped immediately. Also, if there are 0 terminals that can be covered even if the transmission power of the neighboring base station is increased from the current state (if there are no more terminals that can be covered even if the transmission power is increased), the transmission power of the base station to be restarted will be increased in stages. You can stop it immediately by not lowering it.

Using FIG. 25, when the restart target base station is stopped. Processing of the base station management device will be described. FIG. 25 is a flow chart showing an example of the processing flow of the base station management device when the restart target base station is stopped.

The processing unit 120 acquires information on the coverage area of each base station from the storage unit 130 (step S901). This coverage area information includes at least maximum coverage area information (latitude, longitude, etc.), but may include coverage area information for each transmission output (maximum, normal, minimum, etc.).

Next, the processing unit 120 acquires the location information (latitude, longitude, etc.) of the terminal registered in each base station from the storage unit 130 (step S902). The processing unit 120 acquires the location information of the terminal based on GPS (Global Positioning System) signals, for example.

Next, the processing unit 120 acquires the number of terminals currently registered in the restart target base station from the restart target base station via the communication unit 110 (step S903).

Next, the processing unit 120 determines whether or not there is a terminal registered in the restart target base station (step S904). That is, it is determined whether or not the number of registered terminals is one or more. If it is determined that there is a registered terminal (Yes in step S904), the processing unit 120 proceeds to step S905. On the other hand, if it is determined that there is no registered terminal (No in step S904), the processing unit 120 proceeds to step S909.

In step S905, the processing unit 120 determines whether or not there is a terminal located within the maximum coverage area of an adjacent base station among the terminals registered in the restart target base station (step S905). If it is determined that the terminal exists within the maximum coverage area of the adjacent base station (Yes in step S905), the process proceeds to step S906. On the other hand, if it is determined that the terminal does not exist within the maximum coverage area of the neighboring base station (No in step S905), the processing unit 120 proceeds to step S909.

In step S906, processing unit 120 transmits a power change instruction (power change message) to each base station (step S906). That is, the processing unit 120 transmits a message to lower the transmission power by one level to the restart target base station, and a message to raise the transmission power by one level to the adjacent base station. Alternatively, the processing unit 120 may transmit a message directly designating the transmission power value to be used to each base station.

In step S907, the processing unit 120 determines whether or not the restart target base station has stopped (step S907). If it is determined that the restart target base station has stopped (Yes in step S907), the processing unit 120 ends the processing of FIG. On the other hand, if it is not determined that the restart target base station has stopped (No in step S907), the processing unit 120 proceeds to step S908.

In step S908, the processing unit 120 waits for a predetermined time (for example, 10 seconds) (step S908). Then, the processing unit 120 proceeds to step S902 and repeats the above-described processing.

Also, in step S909, the processing unit 120 stops the restart target base station (step S909). Specifically, the processing unit 120 transmits a message indicating permission to stop to the restart target base station via the communication unit 110 . The target base station receiving the message immediately shuts down. Then, the processing unit 120 ends the processing of FIG. 25 . By performing such processing, it is possible to omit unnecessary transmission power change processing, thereby improving the efficiency of the processing of the entire system.

Similarly, as an operation using terminal location information, when the base station to be restarted raises its transmission power after restarting, the base station management apparatus 100 specifies the number of terminals in the coverage area when the next transmission power is raised. Then, if the number of terminals is large, the transmission power may be increased little by little over time, and if the number of terminals is small, the transmission power may be increased in a short period of time. In other words, the number of terminals existing in the coverage area may be calculated based on the location information of the terminals, and the transmission power may be changed according to the number of terminals using the method described in the second embodiment.

Processing of the base station management apparatus after restarting the base station to be restarted will be described with reference to FIG. FIG. 26 is a flow chart showing an example of the processing flow of the base station management apparatus after restarting the restart target base station.

First, the processing unit 120 acquires information (latitude, longitude, etc.) on the coverage area of the restart target base station from the storage unit 130 (step S1001). This coverage area information includes coverage areas by transmission power.

Next, the processing unit 120 acquires the location information (latitude and longitude) of the terminal registered in each base station from the storage unit 130 (step S1002).

Next, the processing unit 120 acquires the number of terminals currently registered in the restart target base station from the restart target base station via the communication unit 110 (step S1003).

Next, the processing unit 120 calculates the number of terminals that can be registered (increased number of terminals) when the transmission power of the restart target base station is increased by one level (step S1004). That is, the processing unit 120 calculates the number of terminals located in an area where the coverage area increases (expands) when the transmission power of the restart target base station is increased by one level. In addition, in step S1003, the number of terminals registered with the base station to be restarted in the past before the restart process may be further acquired. Then, using this information, the number of terminals located in areas where the coverage area increases when the transmission power is increased by one level may be calculated. Such processing is effective when accurate location information of all terminals cannot be acquired.

Next, the processing unit 120 determines whether or not the increased number of terminals is less than a predetermined value (step S1005). If determined to be less than the predetermined value (Yes in step S1005), the processing unit 120 proceeds to step S1006. On the other hand, if it is determined to be equal to or greater than the predetermined value (No in step S1005), the processing unit 120 proceeds to step S1007.

In step S1006, the processing unit 120 sets the next change time interval t to a relatively small value (step S1006). Specifically, the processing unit 120 sets t=t1. Then, the processing unit 120 proceeds to step S1008.

In step S1007, the processing unit 120 sets the next change time interval t to a relatively large value (step S1007). Specifically, the processing unit 120 sets t=t2. This t2 is larger than the above t1, and t1 and t2 satisfy the relationship t1<t2. Then, the processing unit 120 proceeds to step S1008.

Next, the processing unit 120 transmits a power change instruction (power change message) to each base station (step S1008). That is, the processing unit 120 transmits a message to increase the transmission power by one level to the restart target base station, and transmits a message to decrease the transmission power by one level to the adjacent base station. This message includes information on the change time interval t set in step S1006 or step S1007. Also, the processing unit 120 may transmit a message designating the transmission power value to be used and the change time interval t to the base station.

Next, the processing unit 120 determines whether or not the target base station is in the normal state (normal output state) (step S1009). That is, the processing unit 120 determines whether or not the power change processing of the target base station has been completed. Specifically, when the output change processing of the restart target base station is completed, the processing unit 120 transmits a message to that effect to the base station management device 100, and whether or not the message has been received. determine whether or not If it is determined that the restart target base station is in the normal state (Yes in step S1009), the processing unit 120 ends the processing of FIG. On the other hand, if it is determined that the restart target base station is not in the normal state (No in step S1009), the processing unit 120 proceeds to step S1010.

Next, the processing unit 120 waits for a predetermined time (for example, 10 seconds) (step S1010). Then, the processing unit 120 advances to step S1002 and repeats the above-described processing.

By executing the above-described processing, the base station management apparatus 100 can minimize the time required for restarting the target base station while preventing the restart target base station from becoming overloaded. .

In the above process, the change time interval t is set according to the number of terminals located in the area where the coverage area increases when the transmission power is raised by one step, but another method may be used. Specifically, the following transmission power (amount of change in transmission power) may be set such that the increase in the number of terminals falls within a predetermined range. For example, if the predetermined range is "5 or more and less than 10" and the current transmission power is P1 (W), if the transmission power is set to P2 (W) (P1 < P2), three terminals If position registration is expected and seven terminals are expected to be registered when P3(W) (P2<P3) is set, the next transmission power is set to P3(W). Even if the transmission power is set to the normal value, if the number of terminals that match the predetermined range does not exist, the transmission power may be set to the normal value.

[Fifth embodiment]
The configuration of the wireless communication system according to the fifth embodiment will be described using FIG. FIG. 27 is a schematic diagram showing the configuration of a wireless communication system according to the fifth embodiment.

As shown in FIG. 27, the wireless communication system 1A includes a first terminal 10-1, a second terminal 10-2, a third terminal 10-3, a fourth terminal 10-4, a fifth terminal 10- 5, a sixth terminal 106, a first base station 200A-1, a second base station 200A-2, and a third base station 200A-3.

In the first to fourth embodiments, the base station management device 100 instructs each base station to perform transmission power control. In the fifth embodiment, there is no base station management device, and each base station exchanges information with each other and autonomously performs transmission power control.

The first base station 200A-1 to the third base station 200A-3 are provided with storage units (not shown) similar to the base station management apparatus 100 shown in FIG. Various data including adjacent base station information, transmission power information, and transmission power change time information illustrated in FIGS. 4 to 6 are stored in the storage unit. However, the adjacent base station information in FIG. 4 only needs to record information on base stations adjacent to the own base station. Also, the transmission power information of FIG. 5 only needs to record the transmission power of its own base station. A management terminal (not shown) used by a system administrator is connected to the network NW.

When the system administrator operates the management terminal and instructs the restart of a specific base station, the instruction is notified to the restart target base station. Upon receiving the restart instruction information from the network NW, the restart target base station reads the information of the adjacent base station from the storage unit and transmits a restart start message to the adjacent base station. This start message contains the date and time when the own base station starts the stop processing. After transmitting the message, the restart target base station reads the transmission power information and the transmission power change time information from the storage unit, and according to them, similarly to the method controlled by the base station management apparatus 100 shown in FIG. Vary the transmit power of the station.

Upon receipt of the restart start message, the adjacent base station reads the transmission power information and the transmission power change time information from the storage section when the restart date and time included in the message arrives, and according to them, the base station management apparatus shown in FIG. It changes the transmission power of its own base station in the same way as 100 controlled.

After completing the restart of the restart target base station, the restart target base station reads the information of the neighboring base station from the storage unit and transmits a restart completion message to the neighboring base station. Then, the restart target base station reads the transmission power information and the transmission power change time information from the storage unit, and according to them, similarly to the method controlled by the base station management apparatus 100 shown in FIG. Vary the output.

Upon receiving the restart completion message, the adjacent base station reads out the transmission power information and the transmission power change time information from the storage unit, and according to them, performs the same control as the base station management apparatus 100 shown in FIG. Vary the transmit power of the station.

According to the fifth embodiment, it is possible to control the transmission output of each base station by coordinating the base stations without using a base station management device, thereby preventing congestion with a simple system configuration. can be done.

Although the embodiments of the present invention have been described above, the embodiments are not limited by the contents of these embodiments. In addition, the components described above include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those within the so-called equivalent range. Furthermore, the components described above can be combined as appropriate. Furthermore, various omissions, replacements, or modifications of components can be made without departing from the gist of the above-described embodiments.

1, 1A wireless communication system 100 base station management device 110, 210 communication unit 120, 220 processing unit 130 storage unit 140 input device 150 display device 200 base station 230 transmission output control unit 240 reception unit 250 transmission unit 260 antenna

Claims (7)

a communication unit that performs information communication with a target base station and an adjacent base station of the target base station;
During a period in which the target base station is activated, the communication unit transmits to the target base station first activation control information for stepwise increasing a transmission output of the target base station, and the adjacent base station a processing unit for transmitting, from the communication unit, second start-up control information for gradually decreasing the transmission power of the adjacent base station in synchronization with the stepwise increase of the transmission power of the target base station. with
The communication unit acquires from the target base station the number of terminal registration requests per unit time in the target base station,
The processing unit determines whether the number of registration requests is less than a predetermined value in a state in which the transmission power of the target base station is set to a predetermined output value smaller than the normal transmission power, and determines whether the number of registration requests is less than a predetermined value. is less than a predetermined value, the first startup control information for raising the transmission power of the target base station by one step, and the second startup control for lowering the transmission power of the adjacent base station by one step. transmitting information from the communication unit;
A base station management device characterized by: A communication unit that performs information communication with a target base station and an adjacent base station of the target base station
When,
During a period in which the target base station is activated, the communication unit transmits to the target base station first activation control information for stepwise increasing a transmission output of the target base station, and the adjacent base station a processing unit for transmitting, from the communication unit, second start-up control information for gradually decreasing the transmission power of the adjacent base station in synchronization with the stepwise increase of the transmission power of the target base station. with
each of the first startup control information and the second startup control information includes a change completion time, which is the time until the change of the transmission power is completed;
When the processing unit is activated after deactivating the target base station, the greater the representative value of the number of terminals registered in the target base station in a predetermined period before deactivating the target base station, the more the setting a longer change completion time included in the first startup control information and the second startup control information;

A base station management device characterized by: A communication unit that performs information communication with a target base station and an adjacent base station of the target base station
When,
During a period in which the target base station is activated, the communication unit transmits to the target base station first activation control information for stepwise increasing a transmission output of the target base station, and the adjacent base station a processing unit for transmitting, from the communication unit, second start-up control information for gradually decreasing the transmission power of the adjacent base station in synchronization with the stepwise increase of the transmission power of the target base station. with
The communication unit acquires from the adjacent base station the number of terminal registration requests per unit time in the adjacent base station,
The processing unit, when stopping the target base station,
determining whether the number of registration requests is less than a predetermined value, and if the number of registration requests is less than the predetermined value, the transmission power of the target base station is reduced step by step. the transmission power of the adjacent base station is transmitted from the communication unit, and the transmission power of the adjacent base station is increased in synchronization with the stepwise reduction of the transmission power of the target base station to the adjacent base station. Transmitting the second stop time control information for increasing from the communication unit;
A base station management device characterized by: A communication unit that performs information communication with a target base station and an adjacent base station of the target base station
When,
During a period in which the target base station is activated, the communication unit transmits to the target base station first activation control information for stepwise increasing a transmission output of the target base station, and the adjacent base station a processing unit for transmitting, from the communication unit, second start-up control information for gradually decreasing the transmission power of the adjacent base station in synchronization with the stepwise increase of the transmission power of the target base station. ,
a storage unit that stores information indicating the maximum coverage area of each of the adjacent base stations and terminal position information indicating the latitude and longitude of the terminal registered in each base station;
The processing unit, when stopping the target base station,
referring to the storage unit, identifying, from among the adjacent base stations stored in the storage unit, an adjacent base station in which the terminal registered with the target base station is included in the maximum coverage area;
transmitting, to the target base station, first outage control information for gradually decreasing a transmission output of the target base station from the communication unit, and transmitting the target base station to the identified adjacent base station; Transmitting from the communication unit second stop time control information for increasing the transmission power of the adjacent base station in synchronization with the stepwise reduction of the transmission power of the station;
A base station management device characterized by: A communication unit that performs information communication with a target base station and an adjacent base station of the target base station
When,
During a period in which the target base station is activated, the communication unit transmits to the target base station first activation control information for stepwise increasing a transmission output of the target base station, and the adjacent base station a processing unit for transmitting, from the communication unit, second start-up control information for gradually decreasing the transmission power of the adjacent base station in synchronization with the stepwise increase of the transmission power of the target base station. ,
a storage unit that stores information indicating a coverage area by transmission power of the target base station and terminal location information indicating the latitude and longitude of a terminal registered in each base station;
each of the first startup control information and the second startup control information includes an output hold time that is a time for holding a constant transmission output;
The processing unit refers to the storage unit during the period in which the target base station is activated, and calculates the number of terminals newly included in the coverage area when the transmission power of the target base station is increased by one level. and setting a longer output holding time included in the first startup control information and the second startup control information as the calculated number of terminals increases;
A base station management device characterized by: a communicating step of communicating information with a target base station and a neighboring base station of said target base station;
during a period of activating the target base station, transmitting to the target base station first activation control information for stepwise increasing the transmission power of the target base station; a processing step of transmitting second start-up control information for gradually decreasing the transmission power of the adjacent base station in synchronization with the gradual increase of the transmission power of the target base station;
A program to be executed by a computer operating as a base station management device ,
the communicating step acquires from the target base station the number of terminal registration requests per unit time in the target base station;
The processing step determines whether or not the number of registration requests is less than a predetermined value in a state in which the transmission power of the target base station is set to a predetermined output value smaller than the normal transmission power; is less than a predetermined value, the first startup control information for raising the transmission power of the target base station by one step, and the second startup control for lowering the transmission power of the adjacent base station by one step. send information,
A program characterized by a communicating step of communicating information with a target base station and a neighboring base station of said target base station;
during a period of activating the target base station, transmitting to the target base station first activation control information for gradually increasing the transmission power of the target base station; a processing step of transmitting second start-up control information for stepwise decreasing the transmission power of the adjacent base station in synchronization with the stepwise increase of the transmission power of the target base station;
A program to be executed by a computer operating as a base station management device,
each of the first startup control information and the second startup control information includes a change completion time, which is the time until the change of the transmission power is completed;
In the processing step, when the target base station is activated after being deactivated, the larger the representative value of the number of terminals registered with the target base station in a predetermined period before deactivating the target base station, the more the setting a longer change completion time included in the first startup control information and the second startup control information;
A program characterized by

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