JP2012114858A - Base station controller, method of the same, and base station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base station controller that implements power saving of a base station which is available to a specific user terminal.SOLUTION: In a radio communication system having a first base station and a second base station which is one of subordinates of the first base station and is available to a specific user terminal, a base station controller connected to the second base station and a switching station comprises: a power supply state acquisition part acquiring the power supply state showing whether power supply of the second base station is on or off from the second base station; a utilization state acquisition part acquiring the utilization state of the second base station by the specific user terminal from the switching station; and a control part controlling on and off of the power supply of the second base station based on the power supply state and the utilization state.

Description

  The present invention relates to a base station control apparatus and method for a wireless communication system, and a base station.

  As a base station used in a wireless communication system, an extremely small base station having a cover area (cell radius) of about several tens of meters has been proposed. A cell formed by such a small base station is called a “femto cell”. The cell radius of the femtocell is extremely small compared to a cell having a cell radius of about several kilometers to 10 km, which is generally called “macrocell”.

  Hereinafter, a small base station forming a femto cell is referred to as a “femto cell base station”, and a base station forming a macro cell is referred to as a “macro cell base station”.

  In a communication system including a base station and a mobile station that communicates with another person by communicating with the base station, the mobile station transmits a transmission request signal for requesting the start of transmission of control information. The base station starts transmission of the control information by receiving the transmission request signal, and stops transmission of the control information when a predetermined transmission stop condition is satisfied. A communication system is known (see Patent Document 1).

  In addition, a first cell is formed, a first base station that performs wireless communication with a mobile station located in the first cell, and a second cell is formed, and the second cell A wireless communication system comprising: a second base station that performs wireless communication with a mobile station located within the first cell, wherein the first base is based on a location status of the mobile station within the second cell. There is known a wireless communication system in which a wireless signal output from a station is started or stopped (see Patent Document 2).

Japanese Patent Laid-Open No. 10-023519 JP 2009-159355 A

  There are various operation modes for Home NB (Home Node B: HNB) and Home eNodeB (Home evolved Node B: HeNB). A usage pattern in which only access is allowed is conceivable. In such HNBs and HeNBs that limit the subscribers that can be used, there may be cases where no subscribers exist in the coverage area for a long time. However, the conventional communication system has a problem that the power of the HNB and the HeNB cannot be switched off even in such a case, and power is wasted.

  An object of the disclosed base station control device is to realize power saving of a base station that can be used by a specific user terminal.

  A base station control device includes: a first base station; and a second base station included under the first base station and usable by a specific user terminal. A power state acquisition unit connected to a switching center and acquiring a power state indicating whether the power of the second base station is on or off from the second base station; and A usage status acquisition unit that acquires the usage status of the second base station, and a control unit that controls power on and off of the second base station based on the power status and the usage status.

  According to the present embodiment, it is possible to realize power saving of a base station that can be used by a specific user terminal.

3 shows a configuration example of a 3G mobile UMTS network. The structural example of the ESP network of a LTE mobile is shown. It is a figure explaining the operation | movement outline | summary of one Embodiment of a radio | wireless communications system. It is a structural example of one Embodiment of a base station control apparatus. It is an example of the user terminal management table stored in a base station control apparatus. It is an example of the femtocell management table stored in a base station control apparatus. It is an example of the power supply state management table stored in a base station control apparatus. It is an example of the handover history table stored in the base station control device. It is an example of the utilization condition table stored in a base station control apparatus. It is an example of the parameter management table stored in a base station control apparatus. It is an example of the location information table stored in a base station control apparatus. It is an example of the position information table stored in a base station control apparatus. It is a structural example of one Embodiment of a femtocell base station. It is a structural example of one Embodiment of the power supply management part of a femtocell base station. It is a flowchart of one Embodiment of the process which switches the power supply of a femtocell base station off. It is a flowchart of one Embodiment of the process which switches on the power supply of a femtocell base station.

  Embodiments will be described below with reference to the drawings.

<Network configuration>
First, a configuration example of a wireless communication system to which the base station control device of this embodiment can be applied will be described.

  1 and 2 show a configuration example of a wireless communication system to which the base station control apparatus of this embodiment can be applied.

  FIG. 1 shows a configuration diagram of a 3G mobile UMTS (Universal Mobile Telecommunications System) network. The UMTS network includes a core network (CN) 100, a public switched telephone network (PSTN) network 102, an Internet (IP) network 104, an access network (RAN) 200, a user terminal (User) Equipment: UE) 300.

  The core network 100 includes a home node B gateway (HNBGW) 110, an exchange station 160, and a home location register (HLR) 180. The switching center 160 includes an MSC (Mobile Switching Center) 162 and a GMSC (Gateway MSC) 164 as circuit switching units, and an SGSN (Serving GPRS Support Node) 166 and a GGSN (Gateway GPRS Support Node) 168 as packet switching units. .

  The access network (RAN) 200 includes a Home NodeB (HNB) 210, a NodeB (NB) 220, and a radio network controller (RNC) 230. Since each part of the above-mentioned component is well known to those skilled in the art, detailed description is omitted in this specification.

  The base station control device of the embodiment may be implemented by a separate device that is incorporated in the HNBGW 110 or arranged at the same position as the HNBGW 110. In addition, the base station of the embodiment may be implemented by a separate device that is incorporated in the HNB 210 or connected to the HNB 210.

  FIG. 2 shows a configuration example of an LTE Mobile ESP (Evolved Packet System) network. The ESP network includes a core network (CN) 100, an Internet (IP) network 104, an access network (RAN) 200, and a user terminal (UE) 300.

  The core network 100 includes a Home eNodeB gateway (Home evolved Node B Gateway: HeNBGW) 110e and an exchange station 160. The switching center 160 includes a packet switching unit (SGSN) 166, a subscriber information management server (HSS) 170, a mobility management entity (MME) 172, a PDN gateway (packet data network Gateway: P-GW). 174, and a Serving Gateway (S-GW) 176.

  The access network (RAN) 200 includes a HeNB 210e and an eNodeB 220e. Since each part of the above-mentioned component is well known to those skilled in the art, detailed description is omitted in this specification. All or some of the components in the core network 100 shown in FIGS. 1 and 2 may be implemented with a single or separate hardware.

  The base station control apparatus of the embodiment may be implemented by a separate apparatus that is incorporated in the HeNBGW 110e or arranged at the same position as the HeNBGW 110e. In addition, the base station of the embodiment may be implemented by a separate device that is incorporated in the HeNB 210e or connected to the HeNB 210.

<Overview of operation>
Next, an operation outline of an embodiment of the wireless communication system will be described.

  FIG. 3 is a diagram for explaining an operation outline of an embodiment of the wireless communication system. As shown in FIG. 3, the base station controller 110 arranged in the core network 100 is connected to the home router and the femtocell base station 210 via a BB (Broad Band) line. Base station control apparatus 110 is connected to macro cell base station 400 via a dedicated line. The user terminal 300 is located in one or both of the femto cell and the macro cell.

  The base station controller 110 inquires of the femtocell base station 210 via the BB line about the power state indicating whether the power of the femtocell base station 210 is on or off. In response to the inquiry from the base station controller 110, the femtocell base station 210 transmits its power state to the base station controller 110 via the BB line.

  Further, the base station control apparatus 110 acquires the usage status of the femtocell base station 210 by the user terminal 3000 from the switching center 160 shown in FIGS. For example, the usage status may be information indicating whether the user terminal (UE) 300 registered in the femtocell base station 210 has made a call or data communication in the past or present via the femtocell base station 210. .

  Based on such a power state and usage state of the femtocell base station 210, the base station control device 110 controls the power on or off of the femtocell base station 210 via the BB line.

  When the possibility that the user terminal 300 uses the femtocell base station 210 is high, it is desirable to switch the power of the femtocell base station 210 on or leave it on. For example, when the user terminal 300 has recently made a call or data communication via the femtocell base station 210, it can be said that there is a high possibility of using the femtocell base station 210 in the near future.

  On the other hand, when the possibility that the user terminal 300 uses the femtocell base station 210 is low, it is desirable to switch off the power of the femtocell base station 210 or keep it off.

  In this manner, power saving of the femtocell base station 210 is achieved by controlling the power supply of the femtocell base station 210 to be on or off.

  Furthermore, the base station control apparatus 110 may control power on or off of the femtocell base station 210 based on the distance between the user terminal 300 and the femtocell base station 210. For example, when a user terminal is in the vicinity of a femto cell boundary, it is likely that the user terminal frequently leaves and enters the femto cell or enters the femto cell in the near future. In such a case, the femtocell base station 210 is switched on or left on in order to prevent frequent switching of the power of the femtocell base station 210 or in preparation for possible use in the near future. It is desirable.

  In order to achieve this, the base station controller 110 calculates the distance between the user terminal 300 and the femtocell base station 210, and if the distance is equal to or less than a predetermined value, It is desirable to switch the power on or leave it on. The position of the user terminal 300 is measured using a GPS function based on a signal from a GPS (Global Positioning System) satellite 500 by the user terminal 300, and is transmitted to the base station controller 110 via a BB line. May be. Alternatively, the position of the user terminal 300 may be measured by the macro cell base station 400 and transmitted to the base station controller 110 via a dedicated line.

<Configuration of base station controller>
Next, a configuration example of an embodiment of the base station control device will be described.

  FIG. 4 shows a configuration example of an embodiment of the base station control device 110. The base station control device 110 includes a power state acquisition unit 112, a location information acquisition unit 114, a usage status acquisition unit 116, a handover history acquisition unit 124, a position acquisition unit 126, a database (DB) 128, and a control unit 130. The usage status acquisition unit 116 includes a call time acquisition unit 118, a data communication amount acquisition unit 120, and a current status acquisition unit 122.

  Each acquisition unit stores the acquired information in a database (DB) 128. The control unit 130 controls the power on or off of the femtocell base station 210 based on the information stored in the DB 128.

  The power state acquisition unit 112 inquires of the femtocell base station 210 about the power state indicating whether the power of the femtocell base station 210 is on or off, and acquires the power state from the femtocell base station 210. The power state indicates whether the femtocell base station 210 is on or off. The inquiry about the power state is performed at predetermined time intervals. This time interval may be set by a network administrator or user and stored in the DB 128.

  The location information acquisition unit 114 includes femtocell location information indicating whether or not the user terminal 300 is within the range of the femtocell base station 210, and macrocell presence that indicates whether or not the user terminal 300 is within the range of the macrocell base station 400. The service area information is acquired from the exchange 160.

  The usage status acquisition unit 116 acquires the usage status of the femtocell base station 210 by the user terminal 300. Specifically, the call time acquisition unit 118 acquires the length of time of a call made within a predetermined past period from the switching center 160. This past predetermined period may be set by the network administrator or user and stored in the DB 128. Further, for example, the predetermined period and the duration of the call may be represented by the number of hours, minutes, or seconds.

  The data communication amount acquisition unit 120 acquires the data communication amount performed within the past predetermined period from the switching center 160. This past predetermined period may be set by the network administrator or user and stored in the DB 128, and may be represented by the number of hours, minutes or seconds. Further, for example, the data communication amount may be represented by the number of packets, the number of bytes, or the number of bits.

  The current status acquisition unit 122 acquires from the switching center 160 whether or not the user terminal 300 is currently making a call or data communication using the femtocell base station 210.

  The handover history acquisition unit 124 acquires, from the switching center 160, the location where the handover has failed among the handovers performed in the past from the macrocell base station 400 to the femtocell base station 210. The location where the handover has failed is stored in the DB 128 as a handover (HO) failure location.

  The position acquisition unit 126 acquires the position of the user terminal 300 from the user terminal 300 or the macro cell base station 400. The position of the user terminal 300 may be represented by latitude and longitude. When the user terminal 300 has a GPS function, the position acquisition unit 126 acquires a position from the user terminal 300. When the user terminal 300 does not have a GPS function, or when the user terminal 300 cannot receive radio waves from the GPS satellite 500, the position acquisition unit 126 may acquire the position from the macrocell base station 400.

  The DB 128 stores the power status, location information, usage status, HO failure location acquired by the power status acquisition unit 112, the location information acquisition unit 114, the usage status acquisition unit 116, the handover history acquisition unit 124, and the location acquisition unit 126. And the position of the user terminal 300 is stored. Further, the DB 128 also stores parameters necessary for controlling the power source of the femtocell base station 210. The parameters will be described later.

  5A to 5H show examples of various tables stored in the DB 128 of the base station control apparatus 110. FIG. The same number is assigned to the same information through FIGS. 5A to 5H. A duplicate description of the same information is omitted.

  FIG. 5A shows an example of a user terminal management table stored in the base station control device 110. The user terminal management table has a femtocell ID 700 and a user ID 710. The femtocell ID 700 is identification information (ID) for identifying the femtocell base station 210, and the user ID 710 is identification information (ID) for identifying the user terminal 300 that can use the femtocell base station 210. Such information may be acquired from the femtocell base station 210, or may be set by a network administrator or a user.

  The user terminal management table indicates which user terminal 300 can use the femtocell base station 210. The user terminal management tables may be created as many as the number of femtocell base stations 210 for which the base station control device 110 controls power.

  FIG. 5B shows an example of a femtocell management table stored in the base station controller 110. The femto cell management table includes a femto cell ID 700, a macro cell ID 720, and a femto cell position 730. The macro cell ID 720 is identification information (ID) for identifying the macro cell base station 400. The macro cell ID 720 may be acquired from the macro cell base station 400 or set by a network administrator or a user. The femtocell position 730 represents the position of the femtocell base station 210 by latitude and longitude. The femtocell location 730 may be obtained from the femtocell base station 210 or set by a network administrator or user.

  From the femtocell management table, it can be seen which macrocell the femtocell base station 210 is covered with, that is, which macrocell base station 400 the femtocell base station 210 belongs to. A handover can be performed between the femto cell and the macro cell in this table. The femtocell position 730 is used to calculate the distance between the femtocell base station 210 and the user terminal 300 as described later.

  FIG. 5C shows an example of a power state management table stored in the base station controller 110. The power status management table has a femtocell ID 700 and a femtocell power status 740. The femtocell power state 740 represents whether the femtocell base station 210 is powered on or off. The femtocell power state 740 is acquired from the femtocell base station 210 by the power state acquisition unit 112.

  From the power state management table, it can be seen whether the femtocell base station 210 is powered on or off. Based on this, it is determined whether the base station control apparatus 110 executes a process for switching on the power of the femtocell base station 210 or a process for switching it off.

  FIG. 5D shows an example of a handover history table stored in the base station controller 110. The handover history table has a femtocell ID 700, a handover (HO) failure time 750, a HO failure location 760, and a HO failure location accuracy 770. The HO failure time 750 represents the time when the user terminal 300 failed to perform HO from the macro cell base station to the femtocell base station 210, the HO failure position 760 represents the position where the HO has failed by latitude and longitude, and the HO failure position accuracy 770. Represents the accuracy of the HO failure position 760. These pieces of information are acquired from the switching center by the handover history acquisition unit 124. This table may store a history of failures within a predetermined period, such as the past week, a day, or 6 hours, or a history of failures of a predetermined number of times, such as 10 times.

  From the handover history table, it can be known at which position of the femtocell of the femtocell base station 210 the handover has failed in the past. When the user terminal 300 is at the position stored in this table, the handover to the femtocell base station 210 is avoided, and the femtocell base station 210 is prohibited from being turned on. As a result, it is possible to increase the possibility that the macro cell base station 400 maintains the call or data communication even at a position where the handover may fail.

  FIG. 5E shows an example of a usage status table stored in the base station controller 110. The usage status management table includes a user ID 710, a call duration 790, and a data communication amount 800. The call time 790 represents the total time of calls made during a period specified by a call period 860 in FIG. The call time 790 is acquired from the exchange 160 by the call time acquisition unit 118. The data communication amount 800 represents the amount of data communication performed during the period specified by the data communication period 880 in FIG. The data traffic 800 is acquired from the exchange 160 by the data traffic acquisition unit 120.

  The usage status management table shows which user terminal 300 has made how many calls or data communications during a specified period. It is possible to determine whether or not the femtocell base station 210 should be turned on or off by judging the possibility of a future call or data communication based on the call time or data communication volume made in the past.

  FIG. 5F shows an example of a parameter management table stored in the base station controller 110. The parameter management table includes femtocell ID 700, period 810, control presence / absence 820, period 830, distance threshold 840, call time threshold 850, call period 860, data traffic threshold 870, data communication period 880, HO update period 890, and position threshold. 900.

  The period 810 specifies a period during which the parameters 820 to 900 stored in the parameter management table are valid. For example, it is possible to specify 9:00 for the start time and 18:00 for the end time. When different parameters are applied to a plurality of periods, or when the same parameter is applied to a plurality of separate periods, a parameter management table may be created for each period.

  Control presence / absence 820 specifies whether to turn on or off the power of the femtocell base station 210 in the period specified in the period 810. When “monitored”, the power on / off of the femtocell base station 210 is controlled. When “not monitored”, the power on / off of the femtocell base station 210 is not controlled. In the case of “no monitoring”, it can be further specified whether the power of the femtocell base station 210 is always on or always off.

  The period 830 specifies a period for inquiring the femtocell base station 210 about a power state indicating whether the femtocell base station 210 is powered on or off.

  The distance threshold 840 is a reference value for determining that the power of the femtocell base station 210 is switched off or kept off when the distance between the user terminal 300 and the femtocell base station 210 is larger than this value. is there.

  The call time threshold value 850 is a reference value for determining that the power of the femtocell base station 210 is switched on or kept on when the value of the call time 790 in FIG. 5E is larger than this value. In this example, the value “3 minutes” measured within the time period “30 minutes” specified by the call period 860 and stored in the call time 790 in FIG. 5E is the threshold value “5 minutes” specified by the call time threshold value 850. Because it is shorter, the power of the femtocell base station 210 is controlled to be switched off or kept off.

  The call period 860 specifies a period during which the call time 790 should be measured. For example, when the call period 860 is 30 minutes, the total call time from the present to the previous 30 minutes is stored in the call time 790.

  The data traffic threshold 870 is a reference value for determining that the femtocell base station 210 is switched on or kept on when the value of the data traffic 800 in FIG. 5E is larger than this value. In this example, the value “2.3 MB” measured within the period “30 minutes” specified by the data communication period 880 and stored in the data traffic threshold 870 of FIG. 5E is set by the data traffic threshold 870. Since the threshold is greater than “1 MB”, the power of the femtocell base station 210 is controlled to be switched on or kept on.

  The data communication period 880 specifies a period during which the data communication amount 800 should be measured. For example, when the data communication period 880 is 30 minutes, the total value of the data communication amount from the present to the past 30 minutes before is stored in the data communication amount 800.

  The HO update cycle 890 specifies the validity period of the HO failure time 750 and the HO failure position 760 in FIG. 5D. The HO failure time 750 and the HO failure position 760 that have passed the period specified in the HO update cycle 890 are cleared.

  The position threshold value 900 specifies a threshold value of distances that are determined to be the same HO failure position 760. When the distance between the UE position 930 and the HO failure position 760 shown in FIG. 5H is smaller than the position threshold 900, it is determined that both are the same position.

  The parameter management table specifies in what period and according to what criteria the power supply of the femtocell base station 210 should be controlled. When different criteria are applied to a plurality of periods, a plurality of parameter management tables are created.

  FIG. 5G shows an example of a location information table stored in the base station controller 110. The located area information table includes a user ID 710, a macro cell ID 720, a femto cell ID 700, a macro cell located information 910, and a femto cell located information 920.

  The macro cell location information 910 indicates that the user terminal 300 having the user ID 710 is within or outside the macro cell having the macro cell ID 720. The femtocell location information 920 indicates that the user terminal 300 having the user ID 710 is within or outside the femtocell having the femtocell ID 700. These pieces of information are acquired from the exchange 160 by the location information acquisition unit 114.

  From the location information table, it can be determined whether or not the user terminal 300 is within the range of the femtocell base station 210 having the femtocell ID 700 and the macrocell base station 400 having the macrocell ID 720.

  FIG. 5H shows an example of a position information table stored in the base station controller 110. The location information table has a user ID 710, a UE location 930, and an accuracy 940. The UE position 930 represents the position of the user terminal 300 by latitude and longitude. The UE position 930 is measured by the user terminal 300 when the user terminal 300 has a GPS function, and when the user terminal 300 does not have a GPS function or cannot receive radio waves from the GPS satellite 500, the macro cell base station 400. The UE location 930 is acquired from the user terminal 300 or the macro cell base station 400 by the location acquisition unit 126. Accuracy 940 represents the accuracy of UE location 930.

  The position of the user terminal 300 is specified with accuracy 940 by the position information table. The UE location 930 is used together with the femtocell location 730 to determine the distance between the user terminal 300 and the femtocell base station 210.

<Configuration and operation of femtocell base station>
Next, the configuration and operation of the femtocell base station 210 will be described.

  FIG. 6 shows a configuration example of an embodiment of the femtocell base station 210. The femtocell base station 210 includes a power management unit 212, a power source 241, a wireless (RF) communication unit 242, a broadband (BB) communication unit 243, an antenna 244, and a control unit 245.

  The RF communication unit 242 performs wireless communication with the user terminal 300 via the antenna 244. The BB communication unit 243 performs broadband communication with the base station control apparatus 110 via the BB line. The control unit 245 controls the operation of the femtocell base station 210. The power management unit 212 controls on / off of the power supply 241 according to the embodiment. Details of the power management unit 212 will be described with reference to FIG.

  FIG. 7 shows a configuration example of an embodiment of the power management unit 212 of the femtocell base station 210. The power management unit 212 includes a management unit 214, a transmission unit 216, and a reception unit 218.

  The management unit 214 monitors whether the power source 241 is currently on or off. The receiving unit 218 receives an inquiry about the power state indicating whether the power 241 of the femtocell base station 210 is on or off from the power state obtaining unit 112 of the base station control apparatus 110, and notifies the management unit 214 of the power state. . In response to the inquiry, the management unit 214 notifies the transmission unit 216 of the power state. The transmission unit 216 transmits the power state to the power state acquisition unit 112 of the base station control device 110 via the BB line.

  Further, the reception unit 218 receives a command to turn on or off the power source 241 of the femtocell base station 210 from the control unit 130 of the base station control device 110, or a command to keep it on or off, and notifies the management unit 214 To do. The management unit 214 controls the power source 241 of the femtocell base station 210 to be turned on or off according to the command.

<Flowchart of processing for switching off the power of the femtocell base station>
Next, a flowchart of an embodiment of a process for switching off the power supply 241 of the femtocell base station 210 will be described.

  FIG. 8 shows a flowchart of an embodiment of a process in which the base station controller 110 switches off the power supply 241 of the femtocell base station 210. The processing shown in FIG. 8 is executed by each component of the base station control device 110 under the control of the control unit 130 of the base station control device 110 according to the values set in the parameter management table shown in FIG. 5F.

  The process starts in step S802. In step S802, the power state acquisition unit 112 of the base station controller 110 inquires of the power management unit 212 of the femtocell base station 210 whether the power source 241 of the femtocell base station 210 is on or off. The power status acquisition unit 112 acquires the power status of the power source 241 as a response to the inquiry from the power management unit 212. This inquiry is made at a period 830 during the period 810 of the parameter management table shown in FIG. 5F. The acquired power state is stored in the femtocell power state 740 of the power state management table shown in FIG. 5C. The control unit 130 of the base station controller 110 determines whether the power 241 of the femtocell base station 210 is on or off based on the stored femtocell power state 740. If the power state is off in step S802, the process proceeds to step S902 in FIG. If the power state is on in step S802, the process proceeds to step S804.

  In step S804, the location information acquisition unit 114 of the base station control apparatus 110 acquires from the switching center 160 whether or not the user terminal 300 is within the range of the femtocell base station 210. The acquired location information is stored in the femtocell location information 920 of the location information table shown in FIG. 5G. The control unit 130 determines whether the user terminal 300 is “located” or “out of range” in the femtocell based on the stored location information. If it is determined in step S804 that the location information is within the service area, the method proceeds to step S806, and if it is out of service area, the process proceeds to step S814.

  In step S806, the call time acquisition unit 118 included in the usage status acquisition unit 116 of the base station control apparatus 110 acquires the total time length of calls made within a predetermined period from the exchange 160. Here, the predetermined period is specified by the call period 860 of the parameter management table shown in FIG. 5F. The acquired total time length is stored in the call time 790 of the usage status management table shown in FIG. 5E. The control unit 130 compares the stored call time 790 with the call time threshold 850. In this example, 3 minutes is stored in the call time 790, and 5 minutes is specified in the call time threshold 850. If the call time 790 is equal to or greater than the call time threshold 850, the process returns to step S802, and the power state of the femtocell base station 210 is acquired again. In this case, the power of the femtocell base station 210 is not switched off and is kept on. In the case of this example, since the call time 790 is smaller than the call time threshold value 850, the process proceeds to step S808.

  In step S808, the data communication amount acquisition unit 120 included in the usage status acquisition unit 116 of the base station control apparatus 110 acquires the total amount of data communication performed within a predetermined period from the switching center 160. Here, the predetermined period is specified by the data communication period 880 of the parameter management table shown in FIG. 5F. In this example, 30 minutes is specified. The acquired total data communication amount is stored in the data communication amount 800 of the usage status management table shown in FIG. 5E. The control unit 130 compares the stored data traffic 800 with the data traffic threshold 870. In this example, 2.3M is stored in the data traffic 800, and 1 MB is specified in the data traffic threshold 870. If the data traffic 800 is equal to or greater than the data traffic threshold 870, the method returns to step S802, and the power status of the femtocell base station 210 is acquired again. In this case, the power of the femtocell base station 210 is not switched off and is kept on. If the data traffic 800 is smaller than the data traffic threshold 870, the process proceeds to step S810. In this example, since the data communication amount 800 is larger than the data communication amount threshold value 870, the process proceeds to step S802.

  In step S810, the current status acquisition unit 122 included in the usage status acquisition unit 116 of the base station control apparatus 110 determines whether the user terminal 300 is currently in a call or data communication via the femtocell base station 210. From 160. The acquired result may be stored by providing an appropriate item in the usage status management table, or may be directly transmitted from the current status acquisition unit 122 to the control unit 130. The control unit 130 determines whether the user terminal 300 is currently in a call or data communication via the femtocell base station 210 based on the result acquired by the current status acquisition unit 122. If currently in a call or data communication, the method returns to step S802, and the power state of the femtocell base station 210 is acquired again. If not currently in a call or data communication, the method proceeds to step S812.

  In step S812, the control unit 130 turns off the power supply 241 to the reception unit 218 included in the power management unit 212 of the femtocell base station 210 via the BB line in order to switch off the power supply 241 of the femtocell base station 210. Send a command to switch. The power management unit 212 that has received the command switches the power source 241 to OFF. The operation of the power management unit 212 is as described above with reference to FIG.

  After performing Step S812, the process returns to Step S802, and the power state of the femtocell base station 210 is acquired again.

  If it is determined in step S804 that the location information is out of range, the process proceeds to step S814. In step S814, the location information acquisition unit 114 of the base station control apparatus 110 acquires from the switching center 160 whether or not the user terminal 300 is within the range of the macrocell base station 400. The acquired location information is stored in the macro cell location information 910 of the location information table shown in FIG. 5G. Based on the stored macro cell location information 910, the control unit 130 determines whether the user terminal 300 is “located” or “out of range” in the macro cell. If the in-zone information is out of range in step S814, the process proceeds to step S812, and the control unit 130 switches off the power source 241 of the femtocell base station 210 as described above. If it is determined in step S814 that the location information is within the range, the process proceeds to step S816.

  In step S816, the position acquisition unit 126 of the base station control apparatus 110 acquires the position of the user terminal 300 from the user terminal 300 or the macro cell base station 400. The acquired position is stored in the UE position 930 of the position information table shown in FIG. 5H. The method of measuring the position by the user terminal 300 or the macro cell base station 400 is as described above with reference to FIG.

  The control unit 130 calculates the distance between the user terminal 300 and the femtocell base station 210 based on the latitude and longitude of the UE position 930 and the latitude and longitude of the femtocell position 730 in the femtocell management table illustrated in FIG. 5B. To do. The method then proceeds to step S816.

  In step S818, the control unit 130 compares the distance calculated in step S816 with the distance threshold value 840 of the parameter management table shown in FIG. 5F. If it is determined that the distance calculated by the control unit 130 is equal to or smaller than the distance threshold value 840, the method proceeds to step S806, and the flow for determining whether to turn off the power source 241 of the femtocell base station 210 is continued. . If it is determined that the distance calculated by the control unit 130 is greater than the distance threshold value 840, the process proceeds to step S812, and the power source 241 of the femtocell base station 210 is switched off.

  In the above description, the first condition is that only a call less than a predetermined length of time is performed within a predetermined period and less than a predetermined amount of data communication is performed within a predetermined period, or the user terminal 300 is a femtocell as a second condition. The power source 241 is switched off when one of the following conditions is satisfied.

  In another embodiment, the power source 241 may be switched off only when both the first and second conditions are satisfied.

  In still another embodiment, a call time determination (step S806), a data communication amount determination (step S808), a current call or data communication status determination (step S810), and a location status and distance determination (step S814). -One or more of -S818) may be omitted or the order may be changed.

  When a plurality of user terminals 300 are registered in one femtocell base station 210, the above process may be repeated for all registered user terminals 300.

<Flowchart of processing for switching on the power of the femtocell base station>
Next, a flowchart of an embodiment of a process for switching on the power of the femtocell base station will be described.

  FIG. 9 shows a flowchart of an embodiment of a process in which the base station controller 110 switches the power supply 241 of the femtocell base station 210 off. The process shown in FIG. 9 is executed by each component of the base station control apparatus 110 under the control of the control unit 130 of the base station control apparatus 110 according to the values set in the parameter management table shown in FIG. 5F.

  The process starts in step S902. Step S902 is the same as step S814 in FIG. If it is determined in step S902 that the location information is out of range, the process proceeds to step S802 in FIG. If it is determined in step S902 that the location information is within the range, the process proceeds to step S904.

  Step S904 is the same as step S806 in FIG. If the call time 790 is equal to or greater than the call time threshold 850, the process proceeds to step S906. In this example, since the call time 790 (3 minutes) is smaller than the call time threshold value 850 (5 minutes), the process proceeds to step S916.

  Step S916 is the same as step S808 in FIG. 8 described above. If the data traffic 800 is equal to or greater than the data traffic threshold 870, the process proceeds to step S906. If the data traffic 800 is smaller than the data traffic threshold 870, the process proceeds to step S802 in FIG. In the case of this example, since the data traffic 800 (2.3 MB) is larger than the data traffic threshold 870 (1 MB), the process proceeds to step S906.

  Step S906 is the same as step S816 in FIG. 8 described above. Then, the process proceeds to step S908.

  Step S908 is the same as step S818 in FIG. If it is determined that the distance calculated by the control unit 130 is equal to or smaller than the distance threshold value 840, the process proceeds to step S910. If it is determined that the distance calculated by the control unit 130 is greater than the distance threshold value 840, the process proceeds to step S802 in FIG.

  In step S <b> 910, the handover history acquisition unit 124 of the base station management apparatus 110 acquires the time and position where the handover failed from the switching center 160. The acquired time and position are stored in the HO failure time 750 and the HO failure position 760 of the handover history table shown in FIG. 5D, respectively. The control unit 130 compares the latitude and longitude stored in the HO failure location 760 with the latitude and longitude stored in the UE location 930 of the location information table shown in FIG. 5H, so that the two locations are shown in FIG. 5F. It is determined whether or not they are the same within the range of the position threshold 900 of the parameter management table. If the control unit 130 determines that the HO failure position 760 and the UE position 930 are the same, the process proceeds to step S802. In this case, since the user terminal 300 is in a position where the handover has failed in the past, it is highly likely that the user terminal 300 will fail when the handover is performed again. Therefore, handover from the macro cell to the femto cell is avoided, and the power source 241 of the femto cell base station 210 is prohibited from being turned on and is kept off. When the control unit 130 determines that the HO failure position 760 and the UE position 930 are not the same, the process proceeds to S912.

  In step S912, the control unit 130 determines to switch on the power source 241 of the femtocell base station 210, and supplies the power source 241 to the reception unit 218 included in the power management unit 212 of the femtocell base station 210 via the BB line. Send a command to turn on. The power management unit 212 that has received the command switches the power source 241 on. The operation of the power management unit 212 is as described above with reference to FIG. Next, the process proceeds to step S914.

  In step S914, the handover history acquisition unit 124 of the base station control apparatus 110 acquires from the switching center 160 whether or not the handover from the macro cell to the femto cell is successful. The obtained result may be stored with an appropriate item provided in the handover history table, or may be directly transmitted from the handover history obtaining unit 124 to the control unit 130. The control unit 130 determines whether the handover from the macro cell to the femto cell is successful based on the result acquired by the handover history acquisition unit 124. If successful, the process proceeds to step S802 in FIG. If unsuccessful, the process proceeds to step S918.

  In step S918, the handover failure time and position are stored in the HO failure time 750 and HO failure position 760 of the handover history table shown in FIG. 5D, respectively. Next, the process proceeds to step S920.

  Step S920 is the same as step S812 in FIG. Next, the process proceeds to step S802 in FIG.

  In the above description, as a first condition, a call longer than a predetermined time length is performed within a predetermined period and more than a predetermined amount of data communication is performed within a predetermined period, and the user terminal 300 determines that the femtocell is a second condition. The power source 241 was turned on when both of the conditions were met.

  In another embodiment, the power source 241 may be switched on when one of the first and second conditions is satisfied.

  In still another embodiment, one or more of the call duration determination (step S904), the data traffic determination (step S916), and the distance determination (step S908) may be omitted, or the order may be changed. It may be replaced.

  In still another embodiment, determination of location information such as step S814 shown in FIG. 8 may be added.

  When a plurality of user terminals 300 are registered in one femtocell base station 210, the above method may be repeated for all registered user terminals 300.

  Although specific embodiments have been described herein using the specific parameter values shown in FIGS. 5A-H, other values of parameters may be used, such as 1 hour as the talk time threshold 850, for example. Good.

  As described above, the femtocell base station 210 by the user terminal 300 such as the power state of the femtocell base station 210, the femtocell and macrocell location information of the user terminal 300, the call time within a predetermined time, and the data communication amount. By switching on or off the power supply 241 of the femtocell base station 210 on the basis of the usage status, the location where the handover has failed, etc., power saving of the femtocell base station 210 can be realized.

Regarding the above embodiment, the following additional notes are disclosed.
(Appendix 1)
In a wireless communication system having a first base station and a second base station that is included under the first base station and is usable by a specific user terminal, connected to the second base station and an exchange A base station controller,
A power state acquisition unit for acquiring a power state indicating whether the power of the second base station is on or off from the second base station;
A usage status acquisition unit that acquires the usage status of the second base station by the specific user terminal from the exchange;
A control unit for controlling power on and off of the second base station based on the power state and the usage state;
A base station control device.
(Appendix 2)
The usage status indicates that the specific user terminal has made a call over a time threshold within the first predetermined period via the second base station, and the specific user terminal has passed through the second base station. In the case of indicating at least one of data communication that is equal to or greater than the communication amount threshold within the second predetermined period, the control unit switches the power on or keeps it on.
The base station control device according to Supplementary Note 1, wherein
(Appendix 3)
A location information acquisition unit that acquires location information of the second base station and location information of the first base station for the specific user terminal from the exchange,
Further comprising
The control unit indicates that the area information of the second base station indicates that the specific user terminal is not within the area of the second base station, and the area information of the first base station indicates the specific user terminal Indicates that it is not within range of the first base station, switches off the power of the second base station or keeps it off,
The base station control device according to appendix 1 or 2, characterized by the above.
(Appendix 4)
A position acquisition unit for acquiring the position of the specific user terminal;
Further comprising
The control unit, when the position of the specific user terminal is not within a predetermined distance from the second base station, to switch off the power supply or keep it off.
The base station control device according to any one of supplementary notes 1 to 3, wherein
(Appendix 5)
The position of the specific user terminal is measured by the specific user terminal using a GPS function, or is measured by a first base station that accommodates the specific user terminal.
The base station control device according to appendix 4, wherein
(Appendix 6)
A handover history acquisition unit for acquiring a position where the specific user terminal has failed in handover from the first base station to the second base station;
Further comprising
When the specific user terminal is in a position where the handover has failed, the control unit prohibits switching on the power.
The base station control device according to any one of appendices 1 to 5, characterized in that:
(Appendix 7)
In a wireless communication system having a first base station and a second base station that is included under the control of the first base station and that can be used by a specific user terminal, the power of the second base station is turned on and off. A method of controlling,
The second base station is connected to a base station controller and an exchange,
The base station control device has a power state acquisition unit, a usage status acquisition unit, and a control unit,
The method
The power state acquisition unit acquires a power state indicating whether the power of the second base station is on or off from the second base station,
The usage status acquisition unit acquires the usage status of the second base station by the specific user terminal from the exchange,
The control unit controls power on and off of the second base station based on the power state and the usage state;
A method characterized by that.
(Appendix 8)
The usage status indicates that the specific user terminal has made a call over a time threshold within the first predetermined period via the second base station, and the specific user terminal has passed through the second base station. In the case of indicating at least one of data communication that is equal to or greater than the communication amount threshold within the second predetermined period, the control unit switches the power on or keeps it on.
The method according to appendix 7, characterized by:
(Appendix 9)
A location information acquisition unit that acquires location information of the second base station and location information of the first base station for the specific user terminal from the exchange,
Further comprising
The control unit indicates that the area information of the second base station indicates that the specific user terminal is not within the area of the second base station, and the area information of the first base station indicates the specific user terminal Indicates that it is not within range of the first base station, switches off the power of the second base station or keeps it off,
The method according to appendix 7 or 8, characterized in that:
(Appendix 10)
Obtaining the position of the specific user terminal;
The control unit, when the position of the specific user terminal is not within a predetermined distance from the second base station, to switch off the power supply or keep it off.
The method according to any one of appendices 7 to 9, characterized in that:
(Appendix 11)
The position of the specific user terminal is measured by the specific user terminal using a GPS function, or is measured by a first base station that accommodates the specific user terminal.
The method according to appendix 10, characterized by:
(Appendix 12)
Obtaining a location where the specific user terminal has failed in handover from the first base station to the second base station;
When the specific user terminal is in a position where the handover has failed, the control unit prohibits switching on the power.
The method according to any one of appendices 7 to 11, characterized in that:
(Appendix 13)
In a wireless communication system having a first base station and a second base station included under the first base station and usable by a specific user terminal, the first base station connected to an exchange station and a base station controller 2 base stations,
A management unit for managing a power state indicating whether the power of the second base station is on or off;
A receiving unit for receiving an inquiry about the power state from the base station controller;
A transmitter that transmits the power state to the base station controller in response to the inquiry;
Have
The receiving unit is configured to turn on the power of the second base station determined by the base station control device based on the power state and the usage status of the second base station by the specific user terminal acquired from the exchange. Receive command to control off,
The management unit switches the power on or off according to the command.
A base station characterized by that.
(Appendix 14)
The usage status indicates that the specific user terminal has made a call over a time threshold within the first predetermined period via the second base station, and the specific user terminal has passed through the second base station. In the case of indicating at least one of data communication that is equal to or greater than the communication amount threshold within the second predetermined period, the control unit switches the power on or keeps it on.
The base station as set forth in Appendix 13, characterized in that.
(Appendix 15)
The instruction is further determined based on the second base station location information and the first base station location information by the base station controller from the switching center for the specific user terminal,
The command indicates that the location information of the second base station indicates that the specific user terminal is not within the range of the second base station, and the location information of the first base station indicates that the specific user terminal When indicating that it is not within range of the first base station, indicating that the power of the second base station is switched off or kept off;
15. The base station according to appendix 13 or 14, characterized in that.
(Appendix 16)
The command is further determined based on the location of the specific user terminal received by the base station controller from the switching center,
The command indicates that the power is switched off or kept off if the position of the specific user terminal is not within a predetermined distance from the second base station;
The base station according to any one of appendices 13 to 15, characterized in that:
(Appendix 17)
The position of the specific user terminal is measured by the specific user terminal using a GPS function, or is measured by a first base station that accommodates the specific user terminal.
The base station according to supplementary note 16, wherein
(Appendix 18)
The command is further determined based on a location where the specific user terminal has failed in handover from the first base station to the second base station,
The command indicates that the control unit prohibits the power source from being switched on when the specific user terminal is in a position where the handover has failed.
18. The base station control device according to any one of supplementary notes 13 to 17, characterized in that.

DESCRIPTION OF SYMBOLS 100 Core network 102 Public switched telephone line (PSTN) network 104 Internet (IP) network 110 Home NodeB gateway (HNBGW), base station control apparatus 110e Home eNodeB gateway (HeNBGW), base station control apparatus 112 Power supply state acquisition part 114 Existence Area information acquisition unit 116 Usage status acquisition unit 118 Call time acquisition unit 120 Data traffic acquisition unit 122 Current status acquisition unit 124 Handover history acquisition unit 126 Location acquisition unit 128 Database (DB)
130 Controller 160 Switching office 180 Home location register (HLR)
200 Access Network (RAN)
210 Home NodeB (HNB), femtocell base station 210e Home eNodeB (HeNB), femtocell base station 212 Power management unit 214 Management unit 216 Transmission unit 218 Reception unit 220 NodeB
220e eNodeB
230 Radio Control Unit (RNC)
241 Power supply 242 Wireless (RF) communication unit 243 Broadband (BB) communication unit 244 Antenna 245 Control unit 300 User terminal (UE)
400 Macrocell base station 500 GPS satellite

Claims (8)

In a wireless communication system having a first base station and a second base station that is included under the first base station and is usable by a specific user terminal, connected to the second base station and an exchange A base station controller,
A power state acquisition unit for acquiring a power state indicating whether the power of the second base station is on or off from the second base station;
A usage status acquisition unit that acquires the usage status of the second base station by the specific user terminal from the exchange;
A control unit for controlling power on and off of the second base station based on the power state and the usage state;
A base station control device. The usage status indicates that the specific user terminal has made a call over a time threshold within the first predetermined period via the second base station, and the specific user terminal has passed through the second base station. In the case of indicating at least one of data communication that is equal to or greater than the communication amount threshold within the second predetermined period, the control unit switches the power on or keeps it on.
The base station control device according to claim 1. A location information acquisition unit that acquires location information of the second base station and location information of the first base station for the specific user terminal from the exchange,
Further comprising
The control unit indicates that the area information of the second base station indicates that the specific user terminal is not within the area of the second base station, and the area information of the first base station indicates the specific user terminal Indicates that it is not within range of the first base station, switches off the power of the second base station or keeps it off,
The base station control apparatus according to claim 1 or 2, characterized in that A position acquisition unit for acquiring the position of the specific user terminal;
Further comprising
The control unit, when the position of the specific user terminal is not within a predetermined distance from the second base station, to switch off the power supply or keep it off.
The base station control device according to claim 1, wherein the base station control device is a base station control device. The position of the specific user terminal is measured by the specific user terminal using a GPS function, or is measured by a first base station that accommodates the specific user terminal.
The base station control apparatus according to claim 4. A handover history acquisition unit for acquiring a position where the specific user terminal has failed in handover from the first base station to the second base station;
Further comprising
When in the position where the handover has failed, the control unit prohibits switching on the power supply.
The base station control device according to any one of claims 1 to 5, wherein In a wireless communication system having a first base station and a second base station that is included under the control of the first base station and that can be used by a specific user terminal, the power of the second base station is turned on and off. A method of controlling,
The second base station is connected to a base station controller and an exchange,
The base station control device has a power state acquisition unit, a usage status acquisition unit, and a control unit,
The method
The power state acquisition unit acquires a power state indicating whether the power of the second base station is on or off from the second base station,
The usage status acquisition unit acquires the usage status of the second base station by the specific user terminal from the exchange,
The control unit controls power on and off of the second base station based on the power state and the usage state;
A method characterized by that. In a wireless communication system having a first base station and a second base station included under the first base station and usable by a specific user terminal, the first base station connected to an exchange station and a base station controller 2 base stations,
A management unit for managing a power state indicating whether the power of the second base station is on or off;
A receiving unit for receiving an inquiry about the power state from the base station controller;
A transmitter that transmits the power state to the base station controller in response to the inquiry;
Have
The receiving unit is configured to turn on the power of the second base station determined by the base station control device based on the power state and the usage status of the second base station by the specific user terminal acquired from the exchange. Receive command to control off,
The management unit switches the power on or off according to the command.
A base station characterized by that.

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