JP2012039295A - Base station and power saving method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base station and a power saving method of the same capable of canceling a power-saving mode at the appropriate timing for a mobile station.SOLUTION: A femtocell base station 100 comprises: a registered mobile station in-zone inquiry part 123 inquiring if a registered mobile station is in-zone to peripheral base stations; a registered mobile station presence/absence determination part 105 detecting if the registered mobile station is not in own cell as a trigger to shift to a power-saving mode; a first timer 111 setting a cycle time required for inquiring if the registered mobile station is in-zone to peripheral cells as an expiration value; a second timer 112 setting a time required until the power saving is cancelled as the expiration value; a timer control part 113 resetting and starting the first timer 111 and the second timer 112 when shifting to the power-saving mode; and a radio portion power supply control part 104 turning off a radio part 101 when shifting to the power-saving mode and turning on the radio part 101 when detecting the expiration of the second timer 112 to cancel the power-saving mode.

Description

  The present invention relates to a base station and a power saving method for the base station.

  In a building such as a general home or office, a radio communication base station device (femtocell base station or Home Node-B, etc.) that covers a narrow cell (femto cell) with a cell radius of several tens of meters or less Hereinafter, the installation of “Femtocell base station” or “HNB”) is under consideration.

  3GPP (3rd Generation Partnership Project) LTE (Long term evolution) femtocell base stations are limited, for example, when they are installed in a home, the access is restricted only to the family in the home. It is considered to allow access only to group members. Such a cell may be called an access limited cell (CSG cell: Closed Service Group cell).

  In addition, a UE (User Equipment) that is a portable terminal that is permitted to access is preferentially connected to the femtocell base station. That is, when the UE enters the area of the femtocell base station, radio waves of an existing base station (hereinafter referred to as “macrocell” or “macro base station”) having a cell radius larger than that of the femtocell base station can be received. Even so, the small cell radio communication base station apparatus is preferentially connected.

  Currently, in mobile communication systems, small base stations (femtocells) having a narrow cell radius (a radius of several meters to several tens of meters) have been developed and are expected to be installed in each residence. In addition to the mobile communication service (voice call, data communication, etc.), the use of the merit has been studied.

  In a femtocell base station used at home or the like, there is a desire to turn off the power when it is absent for power saving. In manual operation, forgetting to turn off or forgetting to turn on may be inconvenient for the user. As means for determining ON, there are a method of detecting a transmission signal of a mobile station and using a timer.

  In order to receive a transmission signal from a mobile station that has not been located (execute a random access procedure), the base station cannot be realized unless functions such as a synchronization signal, broadcast information transmission, and random access channel reception are in operation. Moreover, if these are always operated, an energy saving effect cannot be obtained.

  Further, on / off at a fixed time cannot respond to an unscheduled action of a registered user. There is a trend to standardize the power saving technology of base stations by 3GPP.

  Patent Document 1 describes a base station and a shutdown method of a mobile communication system. When the base station described in Patent Literature 1 detects a stop instruction of the base station, it determines whether the mobile device exists in the area of the base station, and when the mobile device does not exist in the area of the base station, Control the base station to stop.

  The apparatus and method described in Patent Document 1 detect the absence of a user in a femtocell, and transition to a power saving mode (power off or intermittent operation). In the power saving mode, the power saving mode is canceled by power-on, reception of a transmission signal from the mobile station, or user detection in conjunction with the security system.

JP 2009-182619 A

  However, since the base station and the shutdown method described in Patent Document 1 are configured to cancel the power saving mode by receiving a transmission signal from the mobile station, the mobile station transmits a transmission signal for canceling the power saving mode. There must be. In addition, the power saving mode may not be canceled at an appropriate timing for the mobile station.

  An object of the present invention is to provide a base station capable of canceling a power saving mode at a timing appropriate for a mobile station, and a power saving method for the base station.

  The base station of the present invention is a base station used in a mobile communication system, and a registered mobile local area inquiry unit that inquires of neighboring base stations whether or not the registered mobile station exists, and a registered mobile station exists in its own cell. A registered mobile station presence / absence determining unit that detects that the mobile station is not in service as a transition to the power saving mode, a first timer that sets the registered mobile local area inquiry period to neighboring cells as an expiration value, and the power saving mode. A second timer whose expiration time is an expiration value, a timer control unit that resets and activates the first and second timers at the time of transition to the power saving mode, and a radio unit at the time of transition to the power saving mode. The power supply is turned off, and when the power saving mode is canceled by detecting the expiration of the second timer, the wireless unit power control unit that controls to turn on the power of the wireless unit is adopted.

  A base station power saving method according to the present invention is a base station power saving method used in a mobile communication system, the step of inquiring a neighboring base station whether or not a registered mobile station is located, and a mobile station registered in its own cell. Detecting that the mobile station is not in the power saving mode, and a first timer that sets the registered mobile local area inquiry period to neighboring cells as an expiration value at the time of the power saving mode transition; A timer control step for resetting and starting a second timer whose expiration time is a time until the power saving mode is canceled, and when the power saving mode is entered, the wireless unit is turned off, and the second timer A step of turning on the power of the wireless unit when the power saving mode is canceled due to expiration detection.

  ADVANTAGE OF THE INVENTION According to this invention, a power saving mode can be cancelled | released at an appropriate timing for the user (mobile station) who is going out.

The block diagram which shows the structure of the femtocell base station which concerns on Embodiment 1 of this invention. The flowchart which shows the power saving mode control of the femtocell base station which concerns on the said Embodiment 1. FIG. The figure which shows the example of operation | movement at the time of the power saving mode transition of the femtocell base station which concerns on the said Embodiment 1. The figure which shows the example of operation | movement at the time of the power saving mode of the femtocell base station which concerns on the said Embodiment 1. FIG. The figure which shows the example of the timer change pattern memorize | stored in the timer change pattern memory | storage part of the femtocell base station which concerns on the said Embodiment 1. FIG. The figure which shows the example of operation | movement in the power saving mode of the femtocell base station which concerns on Embodiment 2 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a femtocell base station according to Embodiment 1 of the present invention. In FIG. 1, description of functional blocks not directly related to the power saving method of the base station is omitted.

  This embodiment is an example in which a power saving method for a base station is applied to a power saving method for a femtocell base station.

  As shown in FIG. 1, a femtocell base station 100 includes a radio unit 101, a baseband signal processing unit 102, a base station control information processing unit 103, a radio unit power control unit 104, a registered mobile station presence / absence determination unit 105, a registered mobile A station storage unit 106, a first timer 111, a second timer 112, a timer control unit 113, a timer change pattern storage unit 121, a located state determination unit 122, and a registered moving local area inquiry unit 123 are provided.

  The wireless unit 101 converts a baseband signal into a wireless signal and transmits it during transmission. The radio unit 101 converts the received radio signal into a baseband signal at the time of reception.

  In transmission, the baseband signal processing unit 102 encodes and modulates broadcast information, paging information, a random access channel, data for each user, and control information. In reception, the baseband signal processing unit 102 demodulates and decodes a random access channel, data for each user, and control information.

  The base station control information processing unit 103 performs transmission / reception processing of control data (C-Plane) and user data (U-Plane) transmitted in a wired interface (S1 and X2 in LTE) between inter-station control stations and base stations. I do. The base station control information processing unit 103 processes base station control information and controls the base station.

  The radio unit power control unit 104 controls the power on and off of the radio unit 101. In the present embodiment, the radio unit power control unit 104 detects that there is no registered mobile station located in its own cell in the registered mobile station presence / absence determination unit 105 (in the case of shifting to the power saving mode), The wireless unit 101 is turned off. In addition, when the wireless unit power control unit 104 detects the expiration of the second timer 112 (when the power saving mode is canceled), the wireless unit power control unit 104 turns on the power of the wireless unit 101.

  The registered mobile station presence / absence determining unit 105 detects that the registered mobile station is not located in its own cell when the power saving mode is entered. The state where there is no registered mobile station refers to a state where there is no RRC_CONNECTED_UE in the own cell, for example.

  The registered mobile station storage unit 106 stores mobile stations that can use the own femtocell base station 100.

  The first timer 111 is a timer whose expiration value is a registered mobile local area inquiry cycle for neighboring cells.

  The second timer 112 is a timer whose expiration value is the time until the power saving mode is canceled.

  The timer control unit 113 resets the first timer 111 and the second timer 112 and starts the timer at the time of shifting to the power saving mode. Specifically, the timer control unit 113 performs the following control.

  The timer control unit 113 activates the first timer 111 and the second timer 112 when all of the mobile stations are handed over outside the communication range of the own station, and the registered mobile local area inquiry unit 123, the first timer 111, and Other than the second timer 112 is shifted to the power saving mode.

  The timer control unit 113 changes the expiration times of the first timer 111 and the second timer 112 according to the base station where the registered mobile station is located. The expiration time is short when the mobile station is in a nearby base station, and is long when the mobile station is in a distant base station.

  Here, the femtocell base station 100 holds the in-zone inquiry result and the inquiry time for a plurality of times, estimates the moving direction of the mobile station from these information, and the timer control unit 113 performs the estimation based on the estimated moving direction. When the mobile station is approaching the own station, the expiration time of the second timer 112 is shortened, and when the mobile station is moving away from the own station, the expiration time of the second timer 112 is increased.

  Based on the estimated moving direction, the timer control unit 113 resets the second timer 112 when the mobile station is at the same base station or moves away.

  The timer control unit 113 resets the first timer 111 when making an inquiry to the registered mobile station.

  The timer control unit 113 activates the function that has shifted to the power saving mode when the second timer 112 expires.

  The timer control unit 113 updates the timer values and timer expiration values of the first timer 111 and the second timer 112 according to the timer change pattern determined by the location state determination unit 122 when receiving the registered mobile local area inquiry result. To do.

  The timer change pattern storage unit 121 holds a timer change pattern corresponding to a change in the serving cell of the registered mobile station.

  The location state determination unit 122 refers to the timer change pattern held in the timer change pattern storage unit 121 according to the change of the location cell of the registered mobile station when the registered mobile local area inquiry result is received. Determine the change pattern. The located state determination unit 122 notifies the timer control unit 113 of the determined timer change pattern.

  When the first timer 111 is detected as expired, the registered mobile local area inquiry unit 123 inquires the neighboring cell about the presence / absence of the registered mobile station via the base station control information processing unit 103. The neighboring base station determines the presence / absence of the registered mobile station in the femtocell base station 100 based on, for example, whether the mobile station inquired of its own cell is in the RRC_CONNECTED state.

  Hereinafter, the power saving operation of the femtocell base station 100 configured as described above will be described.

  FIG. 2 is a flowchart showing the power saving mode control of the femtocell base station 100.

  First, in step S1, the femtocell base station 100 determines whether or not it is in a power saving mode. If not in the power saving mode, in step S2, the femtocell base station 100 periodically determines the presence / absence of a mobile station in the service area while the power saving mode is cancelled. The in-zone mobile station presence / absence determination method is determined based on the number of RRC_CONNECTED_UEs in the own cell, for example. Specifically, it is determined whether or not the number of RRC_CONNECTED_UE is zero. When the number of RRC_CONNECTED_UE is not zero, this flow ends.

  As the mobile station 200 moves, the femtocell detects that the number of RRC_CONNECTED_UEs in its own cell has become zero (Yes in Step S2), initialization of the first timer 111 and the second timer 112 in Step S3 and thereafter, And it shifts to a power saving mode after starting.

  That is, in step S3, the timer control unit 113 initializes the first timer 111, and in step S4, the timer control unit 113 initializes the second timer 112.

  In step S5, the timer control unit 113 starts the first timer 111, and in step S6, the timer control unit 113 starts the second timer 112.

  In step S7, the femtocell base station 100 shifts to the power saving mode, turns off the power of the wireless unit 101, and ends this flow.

  In the case of the power saving mode in step S1, the timer control unit 113 determines whether or not the second timer 112 has expired in step S8.

  If the second timer 112 has not expired, in step S9, the timer control unit 113 determines whether or not the first timer 111 has expired. If the first timer 111 has not expired, this flow ends.

  If the first timer 111 has expired, in step S10, the registered mobile local area inquiry unit 123 inquires of neighboring cells whether or not the mobile station registered in the own femtocell base station exists.

  The neighboring cell to be inquired is set when the femtocell base station is installed, and can be easily updated by restarting or updating according to the location change of the own cell or the installed state of the neighboring cell. Inquiries to neighboring cells are made using a wired interface that transmits base station control and mobile station user data and control data.

  In step S11, the in-zone state determination unit 122 determines the in-zone state based on the inquiry result reported from the neighboring cells. The located state determination unit 122 selects a timer change pattern stored in the timer change pattern storage unit 121 from the located state.

  In step S12, the timer control unit 113 updates the timer value and timer expiration value of the first timer 111 in accordance with the timer change pattern determined by the in-zone state determination unit 122. In step S13, the timer of the second timer 112 is updated. Update value and timer expiry value.

  In step S14, the femtocell base station 100 updates the previous serving cell and ends this flow. Specifically, when receiving the inquiry result, the femtocell base station 100 sets the “current cell” as the “previous cell” and the “current cell” as the registered mobile station. Is reported as a macro cell.

  On the other hand, when the second timer 112 expires in step S8, the femtocell base station 100 cancels the power saving mode in step S15, turns on the power of the radio unit 101, and ends this flow.

  The power saving mode control will be described in detail with reference to FIGS.

  FIG. 3 is a diagram illustrating an example of operation when the femtocell base station 100 shifts to the power saving mode. FIG. 4 is a diagram illustrating an operation example of the femtocell base station 100 in the power saving mode. FIG. 5 is a diagram illustrating an example of timer change patterns stored in the timer change pattern storage unit 121 of the femtocell base station 100.

[Operation when entering power saving mode]
As shown in FIG. 3, at the time of shifting to the power saving mode, the mobile station 200 starts with the macro cell # 1 (FIG. 3 (2)) starting from the area in the available femto cell (the point in FIG. 3 (1)). ) And macro cell # 2 (points in FIGS. 3 (3) and (4)) in order, move to macro cell # 1 (point in FIG. 3 (10)) and finally return to the femto cell (FIG. 3 (1)). ) Point) Indicates movement.

  The femtocell base station 100 periodically determines the presence / absence of a mobile station in the service area while the power saving mode is cancelled. The determination method is determined based on, for example, the number of RRC_CONNECTED_UE in the own cell (see step S2 in FIG. 2).

  When the femtocell detects that the number of RRC_CONNECTED_UEs of its own cell has become zero as the mobile station 200 moves, the femtocell shifts to the power saving mode (see step S7 in FIG. 2).

  At the time of shifting to the power saving mode, the first timer 111 and the second timer 112 are initialized. Subsequently, the first timer 111 and the second timer 112 are started. Subsequently, the wireless unit 101 is turned off.

  In FIG. 3, when the mobile station 200 moves (handover) from the femtocell (point in FIG. 3 (1)) to the macro cell # 1 (point in FIG. 3 (2)) in the power saving mode transition, the number of RRC_CONNECTED_UEs becomes zero. To shift to the power saving mode.

[Operation in power saving mode]
As shown in FIG. 4, in the power saving mode, the mobile station 200 is located in the macro cell # 2 (point of FIG. 4 (4)), and then the macro cell # 8 (point of FIG. 4 (5)). A state where the mobile station moves to and is located in the macro cell # 8 is shown.

  When the femtocell base station 100 detects the expiration of the first timer 111, the femtocell base station 100 inquires of the neighboring cells whether or not the mobile station registered in the own femtocell base station 100 exists (see step S10 in FIG. 2). ). The neighboring cell to be inquired is set when the femtocell base station 100 is installed, and can be easily updated by restarting or updating according to the position change of the own cell or the installed state of the neighboring cell.

  The femtocell base station 100 determines the location state based on the inquiry result reported from the neighboring cells (see step S11 in FIG. 2). The timer change pattern stored in the timer change pattern storage unit 121 is selected from the located state. The timer values and timer expiration values of the first timer 111 and the second timer 112 are updated according to the selected timer change pattern (see steps S12 and S13 in FIG. 2).

  In the situation of FIG. 4, it is reported from the macro cell base station # 8 that the registered mobile station is located, and other macro cell base stations (# 1 to 7, # 9 and # 10) It is reported that there is no service area.

  For example, the neighboring cell determines whether or not the registered mobile station is in the service area based on whether the mobile station 200 inquired of its own cell is in the RRC_CONNECTED state.

  Here, at the time of the previous inquiry, it is reported that the mobile station 200 is located in the macro cell # 2, and the registered mobile station is located only from the macro cell base station # 2. When receiving the inquiry result, the femtocell base station 100 sets the “current serving cell” as the “previous serving cell”, and the “current serving cell” is reported as a macro cell in which the registered mobile station is located. And In FIG. 4, when a report from a neighboring cell is received, the macro cell # 2 that has been the “current serving cell” until then is set as the “previous serving cell”, and the “current serving cell” is set as the macro cell #. 8 (see step S14 in FIG. 2).

[Timer change pattern example]
As shown in FIG. 5, the timer change pattern refers to the combination of the macro cell # 2 that is the “previous visited cell” and the macro cell # 8 that is the “current visited cell” according to the pattern of FIG.

  In the example of FIG. 5, the control of the timer in the movement from the macro cell # 2 to the macro cell # 8 is movement in a direction in which the mobile station 200 moves away from the femto cell. Therefore, the control for the first and second timers 112 resets the timer value and extends the expiration value. This is because the inquiry cycle to the peripheral cells is lengthened, the inquiry frequency is reduced, and the time until the power saving mode is released is lengthened.

  The state of control is not limited to the state in FIG. 5, and a specific numerical value or a state suitable for the situation can be set in the operation to which the present invention is applied. Further, it can be easily updated by restarting or updating according to the position change of the own cell or the installation state of the neighboring cells.

[Operation to cancel power saving mode]
In the power saving mode, the femtocell base station 100 determines whether to cancel the power saving mode. Specifically, when the femtocell base station 100 detects the expiration of the second timer 112 during the power saving mode (see Yes in step S8 in FIG. 2), the femtocell base station 100 cancels the power saving mode, The power is turned on (see step S15 in FIG. 2).

  As described above in detail, according to the present embodiment, the femtocell base station 100 registers the registered mobile local area inquiry unit 123 that inquires the neighboring base station whether or not the registered mobile station is in the area, and the own cell. And a registered mobile station presence / absence determining unit 105 that detects that the mobile station is not located when the power saving mode is entered. In addition, the femtocell base station 100 includes a first timer 111 whose expiration value is a registered mobile local area inquiry cycle for neighboring cells, and a second timer 112 whose expiration time is a time until the power saving mode is canceled. Is provided. Further, the femtocell base station 100 turns off the power of the timer control unit 113 that resets and activates the first timer 111 and the second timer 112 when the power saving mode is shifted, and the radio unit 101 when the power saving mode is shifted. The wireless unit power control unit 104 that turns on the power of the wireless unit 101 when the power saving mode is canceled by detecting the expiration of the second timer 112 is provided.

  With the above configuration, the mobile station 200 registered in the femtocell base station 100 can estimate the time until the mobile station 200 enters the own cell again from the existing state in the surrounding cells, and the radio unit 101 is turned on. The time until can be changed dynamically. Therefore, the power saving mode can be canceled (the power of the wireless unit 101 can be turned on) at an appropriate timing for the user (mobile station). Power saving can be realized by controlling on / off of the power supply of the wireless unit 101 according to the presence or absence of the registered mobile station.

(Embodiment 2)
FIG. 6 is a diagram illustrating an example of operation in the power saving mode of the femtocell base station according to Embodiment 2 of the present invention. The same components as those in FIG. 3 are denoted by the same reference numerals, and description of overlapping portions is omitted.

  The basic configuration and operation of the mobile radio terminal in the second embodiment of the present invention are the same as those in the first embodiment.

  The present embodiment employs a configuration in which the location information of the mobile station in Embodiment 1 is replaced with the location information managed by the management server from the presence / absence of the location of the registered mobile station in the neighboring cell.

  For example, the mobile station measures using GPS (Global Positioning System), PRS (Positioning Reference Signals), etc., and uses it as position information managed by a management server such as MME (Mobility Management Entity). Change to the management server.

  Along with the change of the form of the position information, the information for referring to the timer change pattern is changed from the “previous visited cell” and the “current visited cell” to the distance between the femtocell base station 100 and the mobile station.

  In referring to the timer change pattern, the distance between the femtocell base station 100 and the mobile station is widened, or the timer value and the timer expiration value are directly calculated from the distance.

  The operation is the same as in the first embodiment, and the same effect can be obtained.

  The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this.

  For example, in the above embodiment, the base station is described as a femtocell base station, but the base station may be a picocell, a microcell, an IMCS (Inbuilding Mobile Communication System), or the like.

  Moreover, even if it is not a femtocell base station, it is applicable if it is CSG (Closed Subscriber Group) Cell which can be used only by the registered user, or the Hybrid Cell which schedules the registered user preferentially.

  In each of the above embodiments, the name of the base station and the power saving method of the base station is used. However, this is for convenience of explanation, and the apparatus is a femtocell base station, a mobile communication system, and the method is a power saving control method. There may be.

  Furthermore, each component which comprises the said femtocell base station, for example, each timer, the kind of determination part, etc. are not restricted to embodiment mentioned above.

  Although cases have been described with the above embodiment as examples where the present invention is configured by hardware, the present invention can also be realized by software.

  Each functional block used in the description of each of the above embodiments is typically realized as an LSI which is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. The name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

  Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

  Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. For example, biotechnology can be applied.

  INDUSTRIAL APPLICABILITY The base station and the base station power saving method of the present invention are useful for applications such as mobile communication systems that use femtocell base stations for power saving.

DESCRIPTION OF SYMBOLS 100 Femtocell base station 101 Radio | wireless part 102 Baseband signal processing part 103 Base station control information processing part 104 Radio | wireless part power supply control part 105 Registered mobile station presence determination part 106 Registered mobile station memory | storage part 111 1st timer 112 2nd timer 113 Timer Control unit 121 Timer change pattern storage unit 122 Location state determination unit 123 Registered mobile local area inquiry unit 200 Mobile station

Claims (15)

A base station used in a mobile communication system,
Registered mobile local area inquiry section that inquires about the presence or absence of the registered mobile station in the surrounding base station,
A registered mobile station presence / absence determining unit that detects that the registered mobile station is not located in the own cell as a transition to the power saving mode;
A first timer whose expiration value is the registered mobile local area inquiry cycle to neighboring cells;
A second timer whose expiration time is a time until the power saving mode is canceled;
A timer control unit that resets and activates the first and second timers during the power saving mode transition;
A wireless unit power control unit that controls to turn on the power of the wireless unit when the power of the wireless unit is turned off at the time of the power saving mode transition, and when the power saving mode is canceled by detecting the expiration of the second timer;
A base station comprising: The registered mobile station presence / absence determining unit includes:
The base station according to claim 1, wherein it is determined that there is no RRC_CONNECTED_UE in the own cell that the registered mobile station is not located in the own cell. The registered mobile localization sphere inquiry unit
The base station according to claim 1, wherein when the first timer expires, the neighboring base station is inquired about the presence / absence of a registered mobile station. The timer control unit
The first and second timers are started when all of the mobile stations are handed over outside the communication range of the mobile station, and the power saving mode is set except for the registered mobile local area inquiry unit and the first and second timers. The base station according to claim 1, wherein The timer control unit
The base station according to claim 1, wherein expiration times of the first and second timers are changed according to a base station where a registered mobile station is located.   The base station according to claim 5, wherein the expiration time is short when the mobile station is in a nearby base station and is long when the mobile station is in a distant base station.   The base station according to claim 1, further comprising: an estimation unit that holds the inquiry result and the inquiry time for a plurality of times and estimates the moving direction of the mobile station from the information. The timer control unit
Based on the estimated moving direction, when the mobile station is approaching the own station, the expiration time of the second timer is shortened, and when the mobile station is moving away from the own station, the expiration time of the second timer is set. The base station according to claim 7, wherein the base station is lengthened. The timer control unit
The base station according to claim 7, wherein the second timer is reset when the mobile station is in the same base station or away from the mobile station based on the estimated moving direction. The timer control unit
The base station according to claim 1, wherein the first timer is reset at the time of inquiry of a registered mobile station. The timer control unit
The base station according to claim 1, wherein when the time of the second timer expires, the function that has shifted to the power saving mode is activated. A timer change pattern storage unit that holds a timer change pattern according to a change in the cell of the registered mobile station;
A location where a timer change pattern is determined by referring to a timer change pattern held in the timer change pattern storage unit in response to a change in a location cell of a registered mobile station upon reception of the registered mobile local area inquiry result A state determination unit,
The timer control unit
2. The base station according to claim 1, wherein upon receiving the registered mobile local area inquiry result, the timer value and the timer expiration value of the first and second timers are updated according to a timer change pattern determined by the area state determination unit. .   The base station according to claim 1, wherein the position information of the mobile station is set as position information managed by a management server, and the inquiry destination of the position information is the management server. A power saving method of a base station used in a mobile communication system,
Inquiring to the neighboring base station whether the registered mobile station is in service,
Detecting that the registered mobile station is not located in the own cell as a transition to the power saving mode;
At the time of shifting to the power saving mode,
A timer control step for resetting and starting a first timer whose expiration value is the registered mobile local area inquiry cycle to neighboring cells and a second timer whose expiration time is the time until the power saving mode is canceled; ,
Turning off the power of the wireless unit at the time of transition to the power saving mode, and turning on the power of the wireless unit when the power saving mode is canceled by detecting the expiration of the second timer;
A base station power saving method. Holding a timer change pattern according to a change in the cell of the registered mobile station; and
A step of determining a timer change pattern by referring to the held timer change pattern in accordance with a change in the cell of the registered mobile station when the registered mobile local area inquiry result is received,
In the timer control step,
The base station according to claim 14, wherein upon receiving the registered mobile local area inquiry result, the timer value and the timer expiration value of the first and second timers are updated according to a timer change pattern determined by the in-zone state determination unit. Power saving method.

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