JP2015008398A - Communication system, base station, communication method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which if a radio base station unnecessarily shifts another base station to an active state (cancels a power saving state), for example, at a short cycle, the other radio base station cannot reduce power consumption.SOLUTION: A communication system of the invention includes: a first base station that manages a first cell, and connects with a communication terminal in the first cell; and a second base station that manages a second cell at least part of which overlaps with the first cell, and connects with a communication terminal in the second cell. The second base station is configured to be able to switch between a first state and a second state in which power consumption is lower than the first state per managed cell. In response to the first cell satisfying a predetermined condition, the first base station requests the second base station to switch the second cell in the second state to the first state.

Description

  The present invention relates to a communication system, a base station, a communication method, and a program. In particular, the present invention relates to a base station connected to a communication terminal, a communication system including the base station, a communication method, and a program.

  In a wireless communication system, there is a technology for securing a communication band of a communication terminal by the cells of the plurality of base stations even when the cells of the plurality of base stations are overlapped in a predetermined area and communication terminals are concentrated in the area. is there.

  Patent Document 1 discloses a large base station with a wide radio wave coverage, a small base station with a narrow radio wave reach within the radio wave reach of the large base station, a management device that controls activation of the small base station, and And a management apparatus adaptively activates a small base station. In the wireless communication system of Patent Literature 1, the management apparatus determines whether or not a predetermined condition is satisfied for each radio wave arrival direction within the radio wave arrival range of the large base station. A signal for starting the small base station is transmitted to the small base station located in the direction. As described above, the management device of the wireless communication system can secure the communication band of the communication terminal by activating the small base station when the communication terminal is concentrated in a predetermined area, for example.

  However, in the technique described in Patent Document 1, the management device, which is a device different from the base station, grasps the location status and communication status within the radio wave reach of the large base station, and according to the grasped status, A signal for starting the small base station is transmitted. That is, the technique described in Patent Document 1 requires a management device for controlling the activation of a base station and a cell, and there is a problem in securing a place where the management device is installed and generating capital investment in the management device. Become.

  On the other hand, there is a technique in which the base station itself controls activation of a cell managed by a base station or a cell managed by an adjacent base station without using a management device. For example, 3GPP (3rd Generation Partnership Project) specifies a technology for a base station to stop connecting to a communication terminal and reduce power consumption in a cell to be managed in order to save power in a wireless communication system. Yes.

  Non-Patent Document 1 discloses that a base station transmits ENB CONFIGURATION UPDATE in order to notify an adjacent base station of increase / decrease of cells to be managed. The adjacent base station grasps the cell in which the connection between the base station and the communication terminal is stopped by the received ENB CONFIGURATION UPDATE.

  On the other hand, Non-Patent Document 1 discloses that a base station activates a cell in which connection with a communication terminal is stopped for an adjacent base station (transmits a reference signal (broadcast) in the cell). , CELL ACTIVATION REQUEST is disclosed. The adjacent base station shifts the cell specified by the received CELL ACTIVATION REQUEST to an active state (a state in which a reference signal (broadcast) is transmitted), and enables connection with a communication terminal in the cell.

  Further, in Patent Document 2, when a radio base station satisfies a predetermined condition, another radio base station is switched from an active state to an inactive state (a state in which power consumption is reduced: a power saving state). , ENB CONFIGURATION UPDATE is disclosed. The wireless base station described in Patent Document 1 is (1) the number of connected terminals is less than a predetermined number, (2) the reception power level of a signal between the wireless terminal and another wireless base station exceeds a predetermined level, (3) When the load level of the other radio base station is less than a predetermined level, the other radio base station is switched to an inactive state.

JP 2011-103570 A JP 2012-5002 A

3GPP TS36.423 V11.4.0

  As described above, Patent Literature 2 discloses a condition for a radio base station to switch another radio base station from an active state to an inactive state. However, Non-Patent Document 1 and Patent Document 2 do not disclose conditions for a radio base station to switch another base station from an inactive state to an active state. Therefore, if the radio base station unnecessarily transitions another base station to an active state such as a short cycle (releases the power saving state), the power consumption of the other radio base station is reduced. There was a problem that it was not possible.

  In order to solve the above-described problem, the present invention prevents a base station from unnecessarily releasing the power saving state of another base station, and can reduce power consumption in the other base station, It is an object to provide a base station, a communication method, and a program.

  A communication system according to the present invention manages a first cell and connects a first base station connected to a communication terminal in the first cell, and a second cell at least partially overlapping the first cell. And a second base station connected to a communication terminal in the second cell, wherein the second base station has a first state and a first state for each cell to be managed. The first base station is configured to be able to switch between the second state in which the power consumption is lower than that in the state, and the first base station is configured to switch the second state in response to the first cell satisfying a predetermined condition. The base station is requested to switch the second cell in the second state to the first state.

  The base station of the present invention manages a first cell, manages a communication unit connected to a communication terminal in the first cell, and a second cell that at least partially overlaps the first cell. In response to another base station connected to a communication terminal in the second cell, the first cell satisfies a predetermined condition, the second cell in the first state is And a control unit that requests switching to a second state in which power consumption is lower than that in the first state.

  The communication method of the present invention manages a first cell, connects to a communication terminal in the first cell, manages a second cell at least partially overlapping with the first cell, and In response to another base station connected to a communication terminal in two cells, the first cell satisfies the predetermined condition, and the second cell in the first state is changed to the first cell. It is requested to switch to the second state in which the power consumption is lower than that in the state.

  The program of the present invention manages a first cell, manages a process for connecting to a communication terminal in the first cell, manages a second cell at least partially overlapping the first cell, and In response to the other base station connected to the communication terminal in the second cell, the first cell satisfies a predetermined condition, the second cell in the first state is changed to the first cell And causing the computer to execute processing for requesting switching to a second state in which power consumption is lower than that in the first state.

  The present invention does not unnecessarily cancel the power saving state of another base station, and thus has an effect of reducing power consumption in the other base station.

It is a figure which shows the example of the communication system of one Embodiment of this invention. It is a figure which shows the example of the communication system in the 1st Embodiment of this invention. It is a figure which shows the structural example of the base station in the 1st Embodiment of this invention. It is a flowchart which shows the operation example of the 1st base station in the 1st Embodiment of this invention. It is a flowchart which shows the operation example of the 2nd base station in the 1st Embodiment of this invention. It is a figure which shows the structural example of the base station in the 2nd Embodiment of this invention. It is a figure which shows the example of cell management DB (database) in the 2nd Embodiment of this invention. It is a figure which shows the example of overlay cell management DB in the 2nd Embodiment of this invention. It is a flowchart which shows the operation example of the 1st base station in the 2nd Embodiment of this invention. It is a flowchart which shows the operation example of the 2nd base station in the 2nd Embodiment of this invention. It is a flowchart which shows the operation example of the 1st base station in the 3rd Embodiment of this invention. It is a sequence diagram which shows the operation example of the communication system in the 3rd Embodiment of this invention.

  First, an outline of an embodiment of the present invention will be described with reference to FIG. Note that the reference numerals of the drawings attached to the outline are attached to the respective elements for convenience as an example for facilitating understanding, and the description of the outline is not intended to be any limitation.

  In the communication system according to the embodiment of the present invention, when a predetermined condition is satisfied, for example, when the number of communication terminals located in a cell managed by the base station is increased, all or part of the cell overlaps with the cell. Cancels a power saving mode (state) of a cell managed by another base station.

  Note that the power saving mode is a state in which, for example, in a cell to be managed, a signal (reference signal (notification)) transmitted to the communication terminal is stopped and the communication terminal is not connected.

  Since the base station cancels the power saving mode (state) when a predetermined condition is satisfied, the power consumption mode (state) is not canceled unnecessarily, and power consumption in other base stations is reduced. Is possible.

  The communication system in one embodiment of the present invention includes a base station 1, a communication terminal 2, and a network 3, as shown in FIG.

  The communication system according to an embodiment of the present invention is, for example, LTE (Long Term Evolution) in 3GPP. Note that the communication system may be another method such as LTE-Advanced.

  A base station 1 shown in FIG. 1 manages a cell, which is a communication area that can provide a service to the communication terminal 2, and can be connected to the communication terminal 2 located in the cell. The base station 1 can transmit a reference signal (broadcast) to the communication terminal 2 in units of cells to be managed.

  As shown in FIG. 1, the communication system according to an embodiment of the present invention includes a plurality of base stations 1. The communication system includes, for example, a base station 1-1 and a base station 1-2. The base station 1-1 and the base station 1-2 communicate with each other via, for example, an X2 interface that is a logical communication path that provides inter-base station communication.

  The base station 1-1 manages the first cell 10 and connects to the communication terminal 2 located in the first cell 10. The base station 1-2 manages the second cell 20 and connects to the communication terminal 2 located in the second cell 20.

  In one embodiment of the present invention, the first cell 10 managed by the base station 1-1 and the second cell 20 managed by the base station 1-2 overlap each other. In the example of FIG. 1, the second cell 20 is included in the first cell 10 and has an overlay configuration (the entire second cell 20 overlaps with the first cell 10). ) However, the second cell 20 does not necessarily have an overlay configuration with the first cell 10, and may have a configuration in which a part thereof overlaps with the first cell 10.

  The base station 1 according to the embodiment of the present invention can set the power saving mode in which the transmission of the reference signal (broadcasting) is stopped and the power consumption is reduced in units of cells to be managed. Further, the base station 1 can cancel the power saving mode and resume the transmission of the reference signal (broadcast) for each cell to be managed.

  In response to a request from another base station 1 (base station 1-1), the base station 1 (base station 1-2) in one embodiment of the present invention saves the cells in the power saving mode among the management cells. The power mode can be canceled and the transmission of the reference signal (notification) can be resumed.

  The other base station 1 (base station 1-1) in the embodiment of the present invention determines that the base station 1 (base station 1- 1) responds when the cell to be managed (first cell) satisfies a predetermined condition. Request 2) to cancel the power saving mode of the cell.

  The other base station 1 (base station 1-1), for example, in response to the number of communication terminals residing in the cell to be managed (first cell 10) being equal to or greater than a predetermined threshold, (Base station 1-2) is requested to cancel the power saving mode of the cell. The other base station 1 (base station 1-1), for example, in response to the communication traffic of the cell to be managed (first cell 10) having reached a predetermined threshold or more, the base station 1 (base station 1) -2) is requested to cancel the power saving mode of the cell.

  The other base station 1 (base station 1-1) is the same as the cell (first cell 10) managed by its own device among the cells in the power saving mode managed by the base station 1 (base station 1-2). Alternatively, a request is made to cancel the power saving mode for a partially overlapping cell (second cell 20).

  As described above, the base station 1 according to an embodiment of the present invention is a cell that is partially or entirely overlapped with the cell and that is in a power saving mode when the cell to be managed satisfies a predetermined condition. Is requested to cancel the power saving mode. In response to the request, the other base station 1 cancels the power saving mode of the cell partially or entirely overlapped with the cell.

  As described above, the base station according to the embodiment of the present invention requests other base stations to cancel the power saving state of the cell in response to satisfying the predetermined condition, and therefore the power saving state is not set. The power consumption in the other base station can be reduced without being canceled as necessary.

  Hereinafter, specific embodiments will be described with reference to the drawings.

<First Embodiment>
The communication system according to the first embodiment of the present invention includes a first base station 1-1, a second base station 1-2, a communication terminal 2, and a network 3, as shown in FIG.

  Note that in the first embodiment of the present invention, description of the same configuration as that of the embodiment of the present invention is omitted.

  The first base station 1-1 manages the cell 10, for example. The first base station 1-1 transmits a reference signal (broadcast) in the cell 10 to be managed, and is connected to the communication terminal 2. In the cell 10, the first base station 1-1 can stop the transmission of the reference signal (notification) and set the power saving mode in which the power consumption is reduced. Moreover, the 1st base station 1-1 can cancel | release the power saving mode of the cell 10, and can restart transmission of a reference signal (broadcasting).

  The second base station 1-2 manages the cell 20, for example. The second base station 1-2 transmits a reference signal (notification) and connects to the communication terminal 2 in the cell 20 to be managed. The second base station 1-2 transmits a reference signal (broadcast) in the cell 20 to be managed, and is connected to the communication terminal 2. In the cell 20, the first base station 1-2 can stop the transmission of the reference signal (notification) and set the power saving mode in which the power consumption is reduced. Also, the second base station 1-2 can cancel the power saving mode of the cell 20 and resume transmission of the reference signal (notification).

  FIG. 3 is a diagram illustrating a configuration example of the base station 1 in the first embodiment of the present invention. In the first embodiment of the present invention, the first base station 1-1 and the second base station 1-2 have the same configuration. Hereinafter, the first base station 1-1 will be described as an example.

  As shown in FIG. 3, the first base station 1-1 includes a communication unit 10 and a control unit 11.

  The communication unit 10 is configured using, for example, a radio frequency (RF) circuit or a baseband (BB) circuit, and functions as means for connecting to the communication device 2 via an antenna (not shown) or the like. The communication unit 10 functions as a means for communicating with another base station 1 (for example, the second base station 1-2).

  The control unit 11 is configured using, for example, a CPU (Central Processing Unit) or the like, and functions as means for providing the functions of the units included in the first base station 1-1.

  As illustrated in FIG. 3, the control unit 11 includes a condition determination unit 110 and a state determination unit 111.

  The condition determination unit 110 detects whether or not the cell 10 managed by the first base station 1-1 satisfies a predetermined condition (or whether or not a predetermined condition is satisfied in the managed cell 10) ( Functions as a means for determining. For example, the condition determination unit 110 detects that the number of communication terminals located in the cell 10 is equal to or greater than a predetermined threshold. For example, the condition determination unit 110 detects that the traffic volume of the cell 10 has become equal to or greater than a predetermined threshold. Note that the condition determination unit 110 has at least one of the number of communication terminals in the first cell being equal to or greater than a predetermined threshold or the traffic volume in the first cell being equal to or greater than a predetermined threshold. In response to the detection, the state determination unit 111 is notified of this.

  The timing when the condition determination unit 110 starts the determination is, for example, when a communication terminal is newly located in the cell 10. Further, the timing at which the condition determination unit 110 starts the determination may be, for example, a predetermined cycle.

  The condition determination unit 110 notifies the state determination unit 111 of the fact when the cell 10 satisfies a predetermined condition.

  In response to the notification from the condition determination unit 110, the state determination unit 111 transmits the cell 20 to the second base station 1-2 that manages the cell 20 partially or entirely overlapped with the cell 10. Request to cancel the power saving mode. For example, the state determination unit 111 transmits a message requesting to cancel the power saving mode of the cell 20 to the second base station 1-2.

  The state determination unit 111 includes, for example, an identifier for uniquely identifying the cell 20 for canceling the power saving mode, in a message transmitted to the second base station 1-2. The second base station 1-2 that receives the message grasps, for example, that the power saving mode of the cell 20 is canceled based on the identifier included in the message. For example, the state determination unit 111 may include, in the message, information indicating the normal mode as information on the state (mode). The second base station 1-2 that receives the message changes the mode of the cell 20 based on, for example, information on the state (mode) included in the message.

  The state determination unit 111 included in the first base station 1-1 saves a cell managed by the first base station 1-1 from another base station 1 (for example, the second base station 1-2). In response to receiving a message requesting to cancel the power mode, the power saving mode of the cell is canceled. For example, when the cell 10 to be managed is in the power saving mode, the first base station 1-1 has received a message requesting cancellation of the power saving mode of the cell 10 from another base station 1, The power saving mode of the cell 10 is canceled and the transmission of the reference signal (notification) is resumed.

  As described above, the second base station 1-2 has the same configuration as that of the first base station 1-1 shown in FIG. Accordingly, the state determination unit 111-2 included in the second base station 1-2 has received a message requesting cancellation of the power saving mode of the cell 20 from the first base station 1-1, The power saving mode of the cell 20 is canceled, and the transmission of the reference signal (notification) is resumed.

  FIG. 4 is a flowchart showing an operation example of the first base station 1-1 in the first embodiment of the present invention. In FIG. 4, as an example of the condition satisfied by the cell 10 to be managed, the case where the number of communication terminals existing in the cell 10 is equal to or greater than a predetermined threshold will be described, but the condition is not limited to this condition. For example, the traffic amount in the cell 10 may be a predetermined threshold value or more.

  In the first embodiment of the present invention, the condition determination unit 110 of the first base station 1-1 determines whether or not the number of communication terminals located in the cell 10 is equal to or greater than a predetermined threshold (S101). ).

  If the number of communication terminals located in the cell 10 is less than the predetermined threshold as a result of the determination by the condition determination unit 110, the process returns to step 101 (S101).

  As a result of the determination by the condition determination unit 110, if the number of communication terminals existing in the cell 10 is equal to or greater than a predetermined threshold, the second base station 1- 1 managing the cell 20 partially or entirely overlapped with the cell 10 2 transmits a message requesting to cancel the power saving mode of the cell 20 (S102).

  FIG. 5 is a flowchart showing an operation example of the second base station 1-2 in the first embodiment of the present invention.

  The second base station 1-2 receives from the first base station 1-1 a message requesting cancellation of the power saving mode of the cell 20 (S201).

  In response to receiving the message, the second base station 1-2 cancels the power saving mode of the cell specified by the message (cell 20 in the example of FIG. 5) and transmits a reference signal (notification). Is resumed (S202).

  As described above, in the first embodiment of the present invention, the first base station 1-1 saves the cell 20 from the second base station 1-2 in response to satisfying a predetermined condition. Request to cancel the power status. Therefore, the first base station 1-1 does not unnecessarily request the second base station 1-2 to cancel the power saving mode of the cell 20, and the second base station 1-2 Power consumption can be reduced.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to the drawings. In the second embodiment, the base station 1 has a cell management database (DB) that stores information on cells to be managed. Further, the base station 1 has an overlay cell management DB that stores information related to cells managed by other base stations 1 that are partially or entirely overlapped with cells to be managed.

  Since the base station 1 according to the second embodiment of the present invention has a cell management DB, the number of communication terminals located in each cell to be managed, the state of the cell (whether it is a normal mode or a power saving mode), etc. It becomes possible to manage. Note that the normal mode is a state in which the cell to be managed can be connected to a communication terminal. In addition, since the base station 1 according to the second embodiment of the present invention has an overlay cell management DB, it is a cell partially or wholly overlapped with a cell managed by the own device, and is managed by another base station 1. It is possible to manage information about the cell to be performed.

  Note that in the second embodiment of the present invention, the description of the same configuration as that of the first embodiment or the first embodiment of the present invention is omitted.

  FIG. 6 is a diagram illustrating a configuration example of the base station 1 in the second embodiment of the present invention. In the second embodiment of the present invention, the first base station 1-1 and the second base station 1-2 have the same configuration. Hereinafter, the first base station 1-1 will be described as an example.

  As shown in FIG. 6, the first base station 1-1 includes a communication unit 10, a control unit 11, a cell information management unit 12, a cell management DB 13, an overlay cell information management unit 14, and an overlay cell management. DB15.

  The cell information management unit 12 functions as a unit that collects information on a cell (for example, the cell 10) managed by the first base station 1-1. For example, the cell information management unit 12 collects information on the cells managed by the first base station 1-1 at a predetermined cycle. For example, when the number of communication terminals 2 located in the cell managed by the first base station 1-1 is increased or decreased, the cell information management unit 12 may collect information on the cell.

  The cell information management unit 12 functions as means for storing the collected information about the cells in the cell management DB 13. For example, the cell information management unit 12 updates the information stored in the cell management DB 13 in a predetermined cycle or in response to collecting the information.

  The cell management DB 13 stores information on cells managed by the first base station 1-1. The cell management DB 13 stores information on the cell in a table format, for example.

  FIG. 7 is a diagram illustrating a configuration example of the cell management DB 13 in the second embodiment of the present invention. The cell management DB 13 stores, for example, information about cells regarding the cells 10, 11, and 12 managed by the first base station 1-1.

  The cell management DB 13 is, for example, a cell managed by the first base station 1-1, a cell identifier of the cell, a cell mode indicating the current state (mode) of the cell, and communication within the cell. The number of communication terminals indicating the number of terminals 2 and a predetermined threshold in the cell are stored in association with each other. Note that the information stored in the cell management DB 13 is not limited to these examples, and may be any information as long as it is information related to the cell managed by the first base station 1-1. An amount may be included. FIG. 7 shows an example of the cell management DB 13. The cell management DB 13 does not need to store all the items shown in FIG. 7, and can be selected as appropriate.

  The cell identifier is an identifier that allows the first base station 1-1 and other base stations to uniquely identify a cell managed by the first base station 1-1. In the example of FIG. 7, the cell identifier “AAAAA” of the cell 10 is stored for the cell 10.

  The cell mode indicates the current state (mode) of the cell. In the second embodiment of the present invention, the cell mode is either the normal mode or the power saving mode. Note that, as described above, the normal mode is a state in which the first base station 1-1 is transmitting a reference signal (notification), and the power saving mode is a state in which the first base station 1-1 has a reference signal ( Notification) transmission is stopped. In the example of FIG. 7, “normal” (mode) that is the current state of the cell 10 is stored for the cell 10.

  The number of communication terminals is the number of communication terminals 2 located in the cell managed by the first base station 1-1. In the example of FIG. 7, “10” that is the number of communication terminals 2 located in the cell 10 is stored for the cell 10.

  The threshold value detects (determines) whether or not the cell 10 managed by the first base station 1-1 satisfies a predetermined condition (or whether or not the predetermined condition is satisfied in the managed cell 10). It is a reference value used for this purpose. The threshold is, for example, the number of communication terminals 2 serving as a reference. The threshold is, for example, a reference traffic amount. The condition determination unit 110 of the first base station 1-1 detects (determines), for example, that the number of communication terminals in the cell 10 is equal to or greater than the threshold value (the number of communication terminals 2). For example, the condition determination unit 110 detects (determines) that the traffic volume in the cell 10 is equal to or greater than the threshold value (traffic volume).

  In the example of FIG. 7, the threshold value “50” of the number of communication terminals in the cell 10 is stored for the cell 10.

  The overlay cell management unit 14 functions as a unit that collects information related to a change in the state of a cell that partially or entirely overlaps with a cell managed by the first base station. The overlay cell management unit 14 receives a notification from the state determination unit 111, for example, in response to the state determination unit 111 requesting a change in the state of a cell that partially or entirely overlaps with the cell 10. Collect information about state changes.

  The overlay cell management unit 14 relates to, for example, a cell partially or entirely overlapped with a cell managed by the first base station 1-1 from another base station 1 (for example, the second base station 1-2). It functions as a means for receiving notification of information. For example, the overlay cell management unit 14 receives a notification of information on the cell 20 that overlaps with the cell 10 from the second base station 1-2.

  The overlay cell management unit 14 functions as means for storing information notified from another base station 1 (for example, the base station 1-2) in the overlay cell DB 15.

  The overlay cell management DB 15 functions as means for storing information related to a cell that is partially or entirely overlapped with a cell managed by the first base station 1-1 and received by the overlay cell management unit 14. The overlay cell management DB 15 stores information on the cell in a table format, for example.

  FIG. 8 is a diagram illustrating a configuration example of the overlay cell management DB 15 in the second exemplary embodiment of the present invention. The overlay cell management DB 15 stores, for example, information related to cells 10, 11, and 12 managed by the first base station 1-1, partially or entirely overlapping with the cell. In the example of FIG. 8, the overlay cell management DB 15 stores information regarding the cell 20 as a cell partially or entirely overlapped with the cell 10. The items stored in the overlay cell management DB 15 are not limited to these items. For example, an identifier for uniquely identifying the base station 1 that manages the cell 20 may be stored.

  The cell identifier is an identifier that allows the first base station 1-1 and other base stations to uniquely identify a cell partially or wholly overlapping with a cell managed by the first base station 1-1. . In the example of FIG. 8, the cell identifier “DDDDD” of the cell 20 is stored for the cell 20 that partially or entirely overlaps with the cell 10.

  The cell mode indicates the current state (mode) of the cell. In the second embodiment of the present invention, the cell mode is either the normal mode or the power saving mode. In the example of FIG. 8, “power saving” (mode) that is the current state of the cell 20 is stored for the cell 20 that partially or entirely overlaps with the cell 10.

  In the second embodiment of the present invention, the condition determination unit 110 included in the first base station 1-1 refers to the cell management DB 13 and determines whether or not the cell 10 satisfies a predetermined condition (or management). Whether or not a predetermined condition is satisfied in the cell 10 to be detected) is detected (determined).

  For example, the condition determination unit 110 refers to the cell management DB 13 and detects that the number of communication terminals located in the cell 10 is equal to or greater than a predetermined threshold. For example, the condition determination unit 110 refers to the cell management DB 13 illustrated in FIG. 7, compares the number of communication terminals stored in association with the cell 10 with a threshold value, and the number of communication terminals is equal to or greater than the threshold value. Detect that.

  For example, the condition determination unit 110 compares the traffic volume of the cell 10 stored in the cell management DB 13 with a threshold value related to the traffic volume, and detects that the traffic volume of the cell 10 is equal to or greater than the threshold value.

  The condition determination unit 110 notifies the state determination unit 111 of the fact when the cell 10 satisfies a predetermined condition.

  In response to the notification from the condition determination unit 110, the state determination unit 111 refers to the overlay cell management DB 15 and the presence / absence of a cell partially or entirely overlapped with the cell 10 and the current state of the cell. Understand the state (mode). The state determination unit 111 refers to the overlay cell management DB 15 illustrated in FIG. 8 and recognizes that the cell 20 that overlaps part or all of the cells 10 is in the power saving mode.

  The state determination unit 111 requests the second base station 1-2 that manages the cell 20 to cancel the power saving mode of the cell 20 that is grasped with reference to the overlay cell management DB 15. For example, the state determination unit 111 transmits a message requesting to cancel the power saving mode of the cell 20 to the second base station 1-2.

  The state determination unit 111 receives a notification of information indicating that the state (mode) of the cell 20 has been changed from the second base station 1-2 after transmitting a message requesting the cancellation of the power saving mode of the cell 20. In response to this, the overlay cell management DB 15 is updated based on the information.

  The state determination unit 111-2 included in the second base station 1-2 receives the message requesting the cancellation of the power saving mode of the cell 20 from the first base station 1-1. The 20 power saving mode is canceled and the transmission of the reference signal (notification) is resumed.

  The state determination unit 111-2 included in the second base station 1-2 receives information indicating that the state (mode) of the cell 20 has been changed in response to the cancellation of the power saving mode of the cell 20. 1 base station 1-1. For example, the state determination unit 111-2 notifies the first base station 1-1 of the identifier “DDDDD” of the cell 20 and information indicating the current state “normal” (mode) of the cell 20. .

  FIG. 9 is a flowchart showing an operation example of the first base station 1-1 in the second embodiment of the present invention. In FIG. 9, the condition that the cell 10 to be managed satisfies is described as an example in which the number of communication terminals existing in the cell 10 is equal to or greater than a predetermined threshold, but the condition is not limited to this condition. For example, the traffic amount in the cell 10 may be a predetermined threshold value or more.

  In the second embodiment of the present invention, the condition determination unit 110 of the first base station 1-1 refers to the cell management DB 13, and the number of communication terminals located in the cell 10 is equal to or greater than a predetermined threshold. Is determined (S301).

  If the number of communication terminals located in the cell 10 is less than the predetermined threshold as a result of the determination by the condition determination unit 110, the process returns to step 301 (S301).

  The state determination unit 111 of the first base station 1-1 refers to the overlay cell management DB 15 according to the number of communication terminals existing in the cell 10 being equal to or greater than a predetermined threshold, and partially Alternatively, the presence / absence of a cell that overlaps all and the current state (mode) of the cell are grasped (S302).

  The state determination unit 111 of the first base station 1-1 cancels the power saving mode of the cell 20 for the second base station 1-2 that manages the cell 20 partially or entirely overlapped with the cell 10. A message requesting is sent (S303).

  The overlay cell information management unit 14 updates the overlay cell management DB 15 in response to receiving a notification of information indicating that the state (mode) of the cell 20 has been changed from the second base station 1-2 (S304). ).

  FIG. 10 is a flowchart showing an operation example of the second base station 1-2 in the second embodiment of the present invention.

  The communication unit 10-2 of the second base station 1-2 receives a message requesting to cancel the power saving mode of the cell 20 from the first base station 1-1 (S401).

  In response to receiving the message, the state determination unit 111-2 of the second base station 1-2 cancels the power saving mode of the cell 20 specified by the message, and transmits a reference signal (notification). It resumes (S402).

  The cell information management unit 12-2 of the second base station 1-2 updates the cell management DB 13-2 in response to releasing the power saving mode of the cell 20 (S403).

  The state determination unit 111-2 of the second base station 1-2 receives information indicating that the state (mode) of the cell 20 has been changed in response to the cancellation of the power saving mode of the cell 20 in the first Notify the base station 1-1.

  Since the base station 1 of the second embodiment of the present invention has the cell management DB 13, for each cell to be managed, the number of communication terminals in the area, the state of the cell (whether the normal mode or the power saving mode), and the like It becomes possible to manage. In addition, since the base station 1 according to the second embodiment of the present invention has the overlay cell management DB 15, it is a cell partially or entirely overlapped with the cell managed by the own device, and is managed by the other base station 1. It is possible to manage information about the cell to be performed.

<Third Embodiment>
A third embodiment of the present invention will be described with reference to the drawings.

  In the third embodiment of the present invention, when the control unit 11 of the base station 1 refers to the cell management DB 13 and the managed cell satisfies a predetermined condition, the cell managed by the base station 1 is set to the normal mode. Functions as a means for switching from the power saving mode to the power saving mode.

  The base station 1 according to the third embodiment of the present invention can switch to the power saving mode again in response to, for example, a cell that has canceled the power saving mode fulfilling a predetermined condition.

  Note that in the third embodiment of the present invention, the description of the same configuration as that of the first embodiment, the first embodiment, and the second embodiment of the present invention is omitted.

  The condition determination unit 110-2 of the second base station 1-2 determines whether or not the cell 20 managed by the second base station 1-2 satisfies a predetermined condition (or a predetermined condition in the managed cell 20). Functions as a means for detecting (determining). For example, the condition determination unit 110-2 detects that the number of communication terminals located in the cell 20 is less than a predetermined threshold. For example, the condition determination unit 110-2 detects that the traffic volume of the cell 20 has become less than a predetermined threshold.

  The timing at which the condition determination unit 110-2 starts the determination is, for example, when the communication terminal 2 that has been in the cell 20 moves to another cell. Further, the timing at which the condition determination unit 110-2 starts the determination may be, for example, a predetermined cycle.

  The condition determination unit 110-2 notifies the state determination unit 111-2 of the base station 1-2 to that effect when the cell 20 satisfies a predetermined condition.

  For example, when the number of communication terminals located in the cell 20 becomes less than a predetermined threshold, the condition determination unit 110-2 notifies the state determination unit 111-2 of that fact. For example, when the communication traffic of the cell 20 becomes less than a predetermined threshold, the condition determination unit 110-2 notifies the state determination unit 111-2 to that effect.

  The state determination unit 111-2 hands over the communication terminal 2 located in the cell 20 to another cell in response to the notification from the condition determination unit 110-2. For example, the state determination unit 111-2 hands over the communication terminal 2 located in the cell 20 to the cell 10 having an overlay configuration with the cell 20.

  The state determination unit 111-2 stops the transmission of the reference signal (broadcast) in the cell 20 in response to all the communication terminals 2 included in the cell 20 being handed over to the cell 10.

  In response to the transition of the cell 20 to the power saving mode (stopping the transmission of the reference signal (broadcast)), the state determination unit 111-2 sends the cell 20 to the first base station 1-1. Is notified of the transition to the power saving mode. For example, the state determination unit 111-2 notifies the first base station 1-1 of the identifier “DDDDD” of the cell 20 and information indicating the current state “power saving” (mode) of the cell 20. To do.

  FIG. 11 is a flowchart showing an operation example of the second base station 1-2 in the third embodiment of the present invention. In FIG. 11, as an example of the condition that the cell 20 to be managed satisfies, the number of communication terminals in the cell 20 is less than a predetermined threshold. However, the condition is not limited to this condition. For example, the traffic volume in the cell 20 may be less than a predetermined threshold.

  In the third embodiment of the present invention, the condition determination unit 110-2 of the second base station 1-2 refers to the cell management DB 13-2, and the number of communication terminals located in the cell 20 is predetermined. It is determined whether it is less than the threshold value (S501).

  If the number of communication terminals residing in the cell 10 is equal to or greater than a predetermined threshold as a result of the determination by the condition determination unit 110-2, the process returns to step 501 (S501).

  The state determination unit 111-2 refers to the cell management DB 13-2 in accordance with the number of communication terminals existing in the cell 20 being less than a predetermined threshold, and a cell partially or entirely overlapped with the cell 20. 10, the communication terminal 2 located in the cell 20 is handed over to the cell 10 (S502).

  The state determination unit 111-2 stops the transmission of the reference signal (broadcast) in the cell 20 in response to all the communication terminals 2 included in the cell 20 being handed over to the cell 10 (S503).

  The cell information management unit 12-2 of the second base station 1-2 updates the cell management DB 13 in response to the transition of the cell 20 to the power saving mode (S504).

  In response to the transition of the cell 20 to the power saving mode (stopping the transmission of the reference signal (broadcast)), the state determination unit 111-2 sends the cell 20 to the first base station 1-1. Is switched to the power saving mode (S505).

  FIG. 12 is a sequence diagram illustrating an operation example of the communication system according to the third embodiment of the present invention. In FIG. 12, as an example, the case where the number of communication terminals located in a cell is less than a predetermined threshold (or more than a threshold) will be described as an example of the predetermined condition. However, the condition is not limited to this condition. For example, the amount of traffic in the cell may be less than a predetermined threshold (or more than a threshold).

  The first base station 1-1 detects that the number of communication terminals in the cell 10 is equal to or greater than a predetermined threshold (S601), and sets the power saving mode of the cell 20 to the second base station 1-2. It is requested to cancel (S602).

  In response to the request, the second base station 1-2 cancels the power saving mode of the cell 20 (S603), and informs the first base station 1-1 that the cell 20 is in the normal mode. Notification is made (S604).

  The second base station 1-2 detects that the number of communication terminals in the cell 20 is less than a predetermined threshold (S605), and transitions the cell 20 to the power saving mode (S606). In response to the transition of the cell 20 to the power saving mode, the second base station notifies the first base station 1-1 that the cell 20 is in the normal mode (S607).

  The base station 1 according to the third embodiment of the present invention can switch to the power saving mode again in response to, for example, a cell that has canceled the power saving mode fulfilling a predetermined condition. Therefore, the second base station 1-2 does not continue the normal mode of the cell 20 for an unnecessarily long time, so that power consumption in the second base station 1-2 can be reduced.

<Fourth Embodiment>
The fourth embodiment of the present invention is a form in which a base station computer, CPU or MPU (Micro-Processing Unit) executes software (program) that realizes the functions of the above-described embodiments. Note that in the fourth embodiment of the present invention, the device that executes the software (program) is not limited to a communication device, and may be any device.

  In the fourth embodiment of the present invention, the base station 1 uses software (program) for realizing the functions of the above-described embodiments via various storage media such as CD-R (Compact Disc Recordable) or a network. get. A program acquired by the base station 1 or a storage medium storing the program constitutes the present invention. The software (program) may be stored in advance in, for example, a predetermined storage unit (not shown) included in the base station 1.

  The computer, CPU, MPU, or the like of the base station 1 reads out the program code of the acquired software (program) and executes it. Accordingly, the base station 1 executes the same processing as that of the base station 1 in each of the above-described embodiments.

  According to the fourth embodiment of the present invention, the present invention can be applied to applications such as a program for realizing the computer, CPU, MPU, or the like of the base station 1.

  A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.

[Appendix 1]
A first base station that manages a first cell and connects to a communication terminal in the first cell;
A second base station that manages a second cell that at least partially overlaps the first cell and connects to a communication terminal in the second cell;
The second base station is configured to be able to switch between a first state and a second state in which power consumption is lower than the first state, for each cell to be managed,
The first base station sends the second cell in the second state to the second base station in response to the first cell satisfying a predetermined condition. A communication system characterized by requesting switching to a state of 1.

[Appendix 2]
The predetermined condition is at least one of the number of communication terminals in the first cell being equal to or greater than a predetermined threshold, or the amount of traffic in the first cell being equal to or greater than a predetermined threshold. The communication system according to supplementary note 1, wherein:

[Appendix 3]
The first base station is
For each cell to be managed, store the number of communication terminals in the cell in association with a predetermined threshold in the cell,
The communication system according to appendix 2, characterized in that, referring to the stored information, it is detected that the number of communication terminals in the first cell is equal to or greater than a predetermined threshold.

[Appendix 4]
The first base station is
For each cell to be managed, the traffic volume in the cell and a predetermined threshold value in the cell are stored in association with each other,
The communication system according to appendix 2 or 3, wherein the stored information is detected to detect that the traffic volume in the first cell is equal to or greater than a predetermined threshold.

[Appendix 5]
The first state is a state in which the cell to be managed is connectable to a communication terminal,
The communication system according to any one of appendices 1 to 4, wherein the second state is a state in which a signal to be transmitted to a communication terminal is stopped in the cell to be managed and is not connected to the communication terminal.

[Appendix 6]
The first base station is
For each cell to manage, store information about the cell that overlaps at least partly with the cell,
With reference to the stored information, grasp the cell to switch from the second state to the first state,
The communication system according to any one of appendices 1 to 5, wherein the second base station is requested to switch the grasped cell to the first state.

[Appendix 7]
When the second base station is requested to switch the second cell to the first state, the second base station switches the second cell from the second state to the first state. The communication system according to any one of appendices 1 to 6, which is characterized.

[Appendix 8]
The second base station is
For each managed cell, store the current state of the cell,
Appendices 1 to 7 wherein the state of the second cell is updated in response to a request from the first base station to switch the second cell to the first state. The communication system described.

[Appendix 9]
In response to switching the second cell, which is in the second state, to the first state, the second base station sends the second cell to the first base station. Notifying that it is in the first state,
9. The supplementary note 1 to 8, wherein the first base station stores that the second cell is in the first state in response to receiving the notification. Communications system.

[Appendix 10]
The second base station is
In response to the second cell satisfying a second predetermined condition, the communication terminal in the second cell is handed over to the first cell;
The communication system according to any one of appendices 1 to 9, wherein the second cell is switched from the first state to the second state in response to completion of the handover.

[Appendix 11]
In response to the second base station switching the second cell to the second state, the second cell is in the second state with respect to the first base station. The communication system according to appendix 10, wherein the communication is notified.

[Appendix 12]
A communication unit that manages the first cell and connects to a communication terminal in the first cell;
The second cell manages a second cell that at least partially overlaps the first cell, and the first cell satisfies a predetermined condition with respect to another base station connected to a communication terminal in the second cell. A control unit that requests to switch the second cell in the first state to the second state in which the power consumption is lower than that in the first state in response to the satisfaction;
A base station characterized by comprising:

[Appendix 13]
The predetermined condition is at least one of the number of communication terminals in the first cell being equal to or greater than a predetermined threshold, or the amount of traffic in the first cell being equal to or greater than a predetermined threshold. The base station as set forth in Appendix 13, characterized in that.

[Appendix 14]
For each cell to be managed, further includes a first storage unit that stores the number of communication terminals in the cell and a predetermined threshold in the cell in association with each other,
The base station according to appendix 13, wherein the control unit detects that the number of communication terminals in the first cell is equal to or greater than a predetermined threshold with reference to the first storage unit. .

[Appendix 15]
For each cell to be managed, it further includes a second storage unit that stores the traffic volume in the cell and a predetermined threshold value in the cell in association with each other,
15. The base station according to appendix 13 or 14, wherein the control unit detects that the traffic amount in the first cell is equal to or greater than a predetermined threshold with reference to the second storage unit. .

[Appendix 16]
The first state is a state in which the cell to be managed is connectable to a communication terminal,
The base station according to any one of appendices 13 to 15, wherein the second state is a state in which a signal transmitted to a communication terminal is stopped in the cell to be managed and is not connected to the communication terminal.

[Appendix 17]
A third storage unit that stores information on a cell that is at least partially overlapped with the cell for each cell to be managed;
The control unit refers to the third storage unit, grasps a cell to be switched from the second state to the first state, and sends the grasped cell to the other base station. 17. The base station according to any one of appendices 13 to 16, wherein the base station is requested to switch to the state of 1.

[Appendix 18]
In response to a request to switch the first cell to the first state when the first cell is in the second state, the control unit moves the first cell to the first state. 18. The base station according to any one of appendices 13 to 17, wherein the base station is switched from a second state to the first state.

[Appendix 19]
In response to switching the first cell, which is the second state, to the first state, the control unit causes the first cell to be transmitted to the other base station. Item 19. The base station according to appendix 18, wherein the base station is notified of the state.

[Appendix 20]
For each cell to be managed, further comprises a fourth storage unit for storing the current state of the cell,
The state of the first cell in the fourth storage unit is updated in response to a request from the other base station to switch the first cell to the first state. The base station according to appendix 18 or 19,

[Appendix 21]
The controller is
In response to the first cell satisfying a second predetermined condition, the communication terminal in the first cell is handed over to the first cell;
The base station according to any one of supplementary notes 13 to 20, wherein the first cell is switched from the first state to the second state in response to completion of the handover.

[Appendix 22]
The control unit notifies the other base station that the first cell is in the second state in response to switching the first cell to the second state. The base station according to appendix 21, wherein the base station is characterized in that

[Appendix 23]
Managing a first cell and connecting to a communication terminal in the first cell;
The second cell manages a second cell that at least partially overlaps the first cell, and the first cell satisfies a predetermined condition with respect to another base station connected to a communication terminal in the second cell. A communication method characterized by requesting switching of the second cell in the first state to the second state in which power consumption is lower than that in the first state in response to satisfying the condition.

[Appendix 24]
The predetermined condition is at least one of the number of communication terminals in the first cell being equal to or greater than a predetermined threshold, or the amount of traffic in the first cell being equal to or greater than a predetermined threshold. 24. The communication method according to appendix 23, wherein

[Appendix 25]
For each cell to be managed, store the number of communication terminals in the cell in association with a predetermined threshold in the cell,
25. The communication method according to appendix 24, wherein referring to the stored information, it is detected that the number of communication terminals in the first cell is equal to or greater than a predetermined threshold.

[Appendix 26]
For each cell to be managed, the traffic volume in the cell and a predetermined threshold value in the cell are stored in association with each other,
26. The communication method according to appendix 24 or 25, wherein referring to the stored information, it is detected that the traffic volume in the first cell is equal to or greater than a predetermined threshold value.

[Appendix 27]
The first state is a state in which the cell to be managed is connectable to a communication terminal,
27. The communication method according to any one of appendices 23 to 26, wherein the second state is a state in which a signal to be transmitted to a communication terminal is stopped in the managed cell and is not connected to the communication terminal.

[Appendix 28]
For each cell to manage, store information about the cell that overlaps at least partly with the cell,
Referencing the stored information, grasping a cell to be switched from the second state to the first state, and switching the grasped cell to the first state with respect to the other base station. 28. The communication method according to any one of appendices 23 to 27, wherein a request is made.

[Appendix 29]
In response to being requested to switch the first cell to the first state when the first cell is in the second state, the first cell is moved from the second state. 29. The communication method according to any one of appendices 23 to 28, wherein the communication method is switched to the first state.

[Appendix 30]
In response to switching the first cell in the second state to the first state, the first cell is in the first state with respect to the other base station. The communication method according to appendix 29, wherein notification is performed.

[Appendix 31]
For each managed cell, store the current state of the cell,
Item 31. The stored first cell state is updated in response to a request to switch the first cell to the first state from the other base station. Communication method.

[Appendix 32]
In response to the first cell satisfying a second predetermined condition, the communication terminal in the first cell is handed over to the first cell;
32. The communication method according to any one of appendices 23 to 31, wherein the first cell is switched from the first state to the second state in response to completion of the handover.

[Appendix 33]
In response to switching the first cell to the second state, the other base station is notified that the first cell is in the second state. The communication method according to attachment 32.

[Appendix 34]
A process of managing the first cell and connecting to a communication terminal in the first cell;
The second cell manages a second cell that at least partially overlaps the first cell, and the first cell satisfies a predetermined condition with respect to another base station connected to a communication terminal in the second cell. Causing the computer to execute a process of requesting to switch the second cell in the first state to the second state in which power consumption is lower than that in the first state in response to satisfying the condition. A program characterized by

[Appendix 35]
The predetermined condition is at least one of the number of communication terminals in the first cell being equal to or greater than a predetermined threshold, or the amount of traffic in the first cell being equal to or greater than a predetermined threshold. 35. The program according to appendix 34, wherein

[Appendix 36]
For each cell to be managed, a process of storing the number of communication terminals in the cell in association with a predetermined threshold in the cell;
36. The program according to appendix 35, including a process of referring to the stored information and detecting that the number of communication terminals in the first cell is equal to or greater than a predetermined threshold.

[Appendix 37]
For each cell to be managed, a process for storing the traffic volume in the cell in association with a predetermined threshold value in the cell;
37. The program according to appendix 35 or 36, including a process of referring to the stored information and detecting that the traffic amount in the first cell is equal to or greater than a predetermined threshold.

[Appendix 38]
The first state is a state in which the cell to be managed is connectable to a communication terminal,
38. The program according to any one of appendices 34 to 37, wherein the second state is a state in which a signal to be transmitted to a communication terminal is stopped in the managed cell and is not connected to the communication terminal.

[Appendix 39]
For each cell to be managed, a process for storing information on a cell that at least partially overlaps the cell;
Referencing the stored information, grasping a cell to be switched from the second state to the first state, and switching the grasped cell to the first state with respect to the other base station. 39. The program according to any one of appendices 34 to 38, including a requesting process.

[Appendix 40]
In response to being requested to switch the first cell to the first state when the first cell is in the second state, the first cell is moved from the second state. 40. The program according to any one of appendices 34 to 39, including a process of switching to the first state.

[Appendix 41]
In response to switching the first cell in the second state to the first state, the first cell is in the first state with respect to the other base station. 41. The program according to appendix 40, including a process of notifying.

[Appendix 42]
For each managed cell, a process for storing the current state of the cell;
A process of updating the stored state of the first cell in response to a request from the other base station to switch the first cell to the first state;
42. The program according to appendix 40 or 41, which includes:

[Appendix 43]
A process of handing over a communication terminal in the first cell to the first cell in response to the first cell satisfying a second predetermined condition;
Processing to switch the first cell from the first state to the second state in response to completion of the handover;
43. The program according to any one of appendices 34 to 42, including:

[Appendix 44]
Including a process of notifying the other base station that the first cell is in the second state in response to switching the first cell to the second state. 44. The program according to appendix 43, which is characterized.

DESCRIPTION OF SYMBOLS 1 Base station 1-1 1st base station 1-2 2nd base station 2 Communication terminal 3 Network 4 1st cell, cell 10
5 Second cell, cell 20
DESCRIPTION OF SYMBOLS 10 Communication part 10-2 Communication part of 2nd base station 11 Control part 12 Cell information management part 12-2 Cell information management part of 2nd base station 13 Cell management DB
13-2 Cell management DB of second base station
14 Overlay information management unit 15 Overlay management DB
110 Condition Determination Unit 110-2 Condition Determination Unit for Second Base Station 111 State Determination Unit 111-2 Second Base Station State Determination Unit

Claims (10)

A first base station that manages a first cell and connects to a communication terminal in the first cell;
A second base station that manages a second cell that at least partially overlaps the first cell and connects to a communication terminal in the second cell;
The second base station is configured to be able to switch between a first state and a second state in which power consumption is lower than the first state, for each cell to be managed,
The first base station sends the second cell in the second state to the second base station in response to the first cell satisfying a predetermined condition. A communication system characterized by requesting switching to a state of 1. The predetermined condition is at least one of the number of communication terminals in the first cell being equal to or greater than a predetermined threshold, or the amount of traffic in the first cell being equal to or greater than a predetermined threshold. The communication system according to claim 2. The first base station is
For each cell to be managed, store the number of communication terminals in the cell in association with a predetermined threshold in the cell,
The communication system according to claim 2, wherein referring to the stored information, it is detected that the number of communication terminals in the first cell is equal to or greater than a predetermined threshold. The first state is a state in which the cell to be managed is connectable to a communication terminal,
4. The communication system according to claim 1, wherein the second state is a state in which a signal to be transmitted to a communication terminal is stopped in the managed cell and is not connected to the communication terminal. 5. . The first base station is
For each cell to manage, store information about the cell that overlaps at least partly with the cell,
With reference to the stored information, grasp the cell to switch from the second state to the first state,
The communication system according to any one of claims 1 to 4, wherein the second base station is requested to switch the grasped cell to the first state. In response to switching the second cell, which is in the second state, to the first state, the second base station sends the second cell to the first base station. Notifying that it is in the first state,
The said 1st base station memorize | stores that the said 2nd cell is a said 1st state according to having received the said notification, The Claim 1 thru | or 5 characterized by the above-mentioned. Communication system. The second base station is
In response to the second cell satisfying a second predetermined condition, the communication terminal in the second cell is handed over to the first cell;
The communication system according to claim 1, wherein the second cell is switched from the first state to the second state in response to completion of the handover. A communication unit that manages the first cell and connects to a communication terminal in the first cell;
The second cell manages a second cell that at least partially overlaps the first cell, and the first cell satisfies a predetermined condition with respect to another base station connected to a communication terminal in the second cell. A control unit that requests to switch the second cell in the first state to the second state in which the power consumption is lower than that in the first state in response to the satisfaction;
A base station characterized by comprising: Managing a first cell and connecting to a communication terminal in the first cell;
The second cell manages a second cell that at least partially overlaps the first cell, and the first cell satisfies a predetermined condition with respect to another base station connected to a communication terminal in the second cell. A communication method characterized by requesting switching of the second cell in the first state to the second state in which power consumption is lower than that in the first state in response to satisfying the condition. A process of managing the first cell and connecting to a communication terminal in the first cell;
The second cell manages a second cell that at least partially overlaps the first cell, and the first cell satisfies a predetermined condition with respect to another base station connected to a communication terminal in the second cell. A process of requesting to switch the second cell in the first state to the second state in which the power consumption is lower than that in the first state in response to satisfying;
A program that causes a computer to execute.

Images