JP5611090B2 - Wireless communication network system - Google Patents

Description

  The present invention relates to a power supply control method for a radio base station, and more particularly to a radio communication network system capable of reducing power consumption of a femto base station in an environment where macro base stations and femto base stations coexist.

In recent years, mobile phone penetration and market expansion, and is progressing diversification of services, 3GPP of (3 ^rd Generation Partnership Project) evolved toward the 4th generation mobile communication technology to achieve a high-speed large-capacity communication even in As one of radio access technologies, standardization of LTE (Long Term Evolution) and LTE-Advanced has been performed. On the other hand, it is predicted that the number of base stations to be installed will increase as the size of the cell advances. In addition, the use of femto base stations is being promoted as a countermeasure to places where base station installation areas are restricted, such as indoors, underground malls, high floors of high-rise buildings, etc., and dead zones due to wireless characteristics, The introduction of small base stations such as femto base stations is expected to increase in the future.

  However, as the number of base stations increases, there is a problem that power consumption in the wireless communication system also increases. For this reason, each standardization organization represented by 3GPP is currently standardizing the “Energy Savings Management” function that realizes power control of the base station and the like for the purpose of reducing the power consumption of the network (for example, non-patent literature) 1). As functions realized by “Energy Savings Management”, restriction of the use frequency, reduction / stop of transmission power, power control of cells and base stations, etc. are considered. In particular, power control of cells and base stations is considered. In this case, realization of area interpolation between base stations and restarting (resume) conditions of base stations are major issues.

JP 2010-212998 A

3GPP TR32.826 KDDI R & D Laboratories, Inc., “Environmentally Considered Macro / Femto Base Station Dynamic Start Control”, The Institute of Electronics, Information and Communication Engineers, IEICE Tech. NS2009-257, March 2010, p. 533-536

  As a conventional technique, the method described in Patent Document 1 is equipped with a GPS (Global Positioning System) function in a mobile phone, and a GPS function mobile phone between a GPS function mobile phone and a position monitoring unit arranged in a macro base station. Communicate location information. The power control of the femto base station is realized by determining whether or not the mobile phone with a GPS function exists in a predetermined area from the position information based on the GPS measurement. This system includes a macro base station including a predetermined area (femto base station area), a femto base station, and a mobile phone with a GPS function. However, since this technology is based on the premise that a GPS function different from the function of the wireless communication system is used, all mobile phones are equipped with a GPS function and further communicate GPS information with the position monitoring means of the macro base station. There was a problem that the method to do must be unified.

  Further, in the method described in Non-Patent Document 2, femto base stations existing under the sector configured by the macro base station are managed by “FAP (Femto Access Point) management server”, and mobile phones having a threshold value or more are within the corresponding sector. The power control of the femto base station in the sector is realized when the mobile phone is in the service area. However, since there are all femto base stations in which the femto base station performing power control exists in the sector constituting the macro base station, there may be femto base stations that are not used after power control of the femto base station. Therefore, there was a problem of consuming unnecessary power.

  The present invention has been made in order to solve the above-described problems, and based on information reported from a terminal, a terminal that estimates and uses available femto base stations around the terminal is used. It is an object of the present invention to obtain a wireless communication network system that can activate a femto base station only when it exists.

The present invention relates to a plurality of macro base stations, a plurality of femto base stations belonging to each of the macro base stations, a plurality of terminals that communicate with each macro base station and each femto base station, and a controlled femto base. A wireless communication network system comprising a database storing a femto base station selection table composed of reception levels, valid flags and status flags of neighboring base stations for each station, wherein the first terminal is a first macro When communicating with a base station, the first terminal detects the first femto base station belonging to the first macro base station as a neighboring base station and detects the first femto base station. A measurement result including at least a cell ID and a reception level related to the base station is reported to the first macro base station, and the first macro base station A handover process is performed by comparing a measurement result of the first femto base station with a measurement result of the first femto base station. After completing the handover process, the measurement result of all base stations reported from the first terminal is used. , Generating the femto base station selection table, setting a valid flag indicating that the reception level has been updated, and when the first terminal is out of the radio area of the first femto base station, When the reception level from the first femto base station deteriorates and the first macro base station detects the first macro base station as a neighboring base station, the first terminal determines at least a cell ID and a reception level related to the first macro base station. The first femto base station compares the reported measurement result of the own base station with the measurement result of the first macro base station. When the over process is performed and it is detected that all terminals do not exist in its own area, the area of the new terminal is monitored for a certain monitoring time, and if the new terminal does not exist, the first terminal The macro base station is notified of the transition to the suspend state, transitions to the suspend state, and after the first macro base station completes the handover process, the first terminal measures the neighboring base stations. When the result is received, the femto base station selection table related to the first femto base station is updated, a valid flag indicating that the reception level has been updated is set, and the suspend state is entered from the first femto base station. In order to set the status flag related to the first femto base station in the femto base station selection table to the effect that the transition to the suspended state is received, When the femto base selection table associated with the first femto base station is updated and the first terminal moves from the radio area of the second macro base station to the radio area of the adjacent first macro base station. In the case where the first femto base station is in the suspended state, the first terminal, when located in the first macro base station, receives the cell ID and reception level of the neighboring base station. The first macro base station reports the measurement result including at least the measurement result reported from the first terminal and the reception level of the femto base station selection table. Except for the reception level in which the status flag indicating the transition to the suspended state is set, the reception level in which the valid flag indicating that the reception level has been updated is compared for each femto base station, and both reception levels are compared. When Le match is in the wireless communication network system such as that characterized by instructing the resume process to the first femto base station.

  According to the wireless communication network system of the present invention, based on information reported from a terminal, an available femto base station existing around the terminal is estimated, and only when there is a terminal to be used, the femto base station Can be activated.

It is a figure which shows the structure of the radio | wireless communication network system which concerns on Embodiment 1 of this invention. It is a figure which shows the relationship between the macro base station area and femto base station area of the radio | wireless communication network system which concerns on Embodiment 1 of this invention. It is a figure which shows the femto base station selection table production | generation sequence of the radio | wireless communication network system which concerns on Embodiment 1 of this invention. It is a figure which shows the example of the femto base station selection table of the radio | wireless communication network system which concerns on Embodiment 1 of this invention. It is a figure which shows the femto base station suspend operation | movement sequence of the radio | wireless communication network system which concerns on Embodiment 1 of this invention. It is a figure which shows the femto base station starting sequence of the radio | wireless communication network system which concerns on Embodiment 1 of this invention. It is a figure which shows the relationship between the macro base station area and femto base station area of the radio | wireless communication network system which concerns on Embodiment 2 of this invention. It is a figure which shows the relationship between the macro base station area and femto base station area of the radio | wireless communication network system which concerns on Embodiment 3 of this invention. It is a figure which shows the position registration sequence at the time of the femto base localization zone of the radio | wireless communication network system which concerns on Embodiment 3 of this invention. It is a figure which shows the example of the user location history information of the radio | wireless communication network system which concerns on Embodiment 3 of this invention. It is a figure which shows the femto base station starting sequence of the radio | wireless communication network system which concerns on Embodiment 3 of this invention. It is a figure which shows the period starting operation | movement of the femto base station of the radio | wireless communication network system which concerns on Embodiment 4 of this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a wireless communication network system of the invention will be described with reference to the drawings.

Embodiment 1 FIG.
A wireless communication network system according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a diagram showing a configuration of a wireless communication network system according to Embodiment 1 of the present invention. In the first embodiment, an embodiment applied to an LTE wireless communication network defined by 3GPP, which is one of standardization organizations, will be described. In the following, in each figure, the same reference numerals indicate the same or corresponding parts.

  In FIG. 1, a radio communication network system according to Embodiment 1 of the present invention is a radio access network composed of macro base stations 10a and 10b installed outdoors and femto base stations 11a and 11b installed indoors. (E-UTRAN: Evolved Universal Terrestrial Radio Access Network) 1, UE (User Equipment) 2 including a terminal 20 such as a mobile phone connected to E-UTRAN 1 using an LTE radio access communication system, and a core network ( EPC: Evolved Packet Core) 3, area design operation device 4 for managing and changing radio parameters of macro base stations 10a and 10b and femto base stations 11a and 11b, and HeNB functioning as a gateway between femto base station 11b and EPC 3 -GW (Home eNodeB Gateway) 5 is provided.

  The core network (EPC) 3 includes a mobility management entity (MME) 30 that manages the mobility of the terminal 20, an S-GW (Serving Gateway) 31 that provides a gateway function for IP communication, and a P- A packet data network gateway (GW) 32 and a home subscriber server (HSS) 33 that manages user subscriber information are provided.

  The femto base stations 11a and 11b can be connected to the EPC 3 via the HeNB-GW 5 and can be directly accommodated in the EPC 3.

  FIG. 2 is a diagram showing the relationship between the macro base station area and the femto base station area in the wireless communication network system according to Embodiment 1 of the present invention.

  FIG. 2 shows the relationship between the radio area 40 in the macro base station 10a and the radio area 50 in the femto base stations 11a and 11b. The femto base stations 11a and 11b belong to at least one macro base station 10a. The macro base station 10a is connected to a database 60 that stores femto base station information belonging to the base station. The database (data storage device) 60 may be mounted in the femto base station or connected as an external device. Further, the macro base station 10b and the macro base station 10a in the vicinity can directly communicate with each other via the X2 interface, and can communicate via the mobility management device (MME) 30 using the S1 interface. It is.

  Next, the operation of the wireless communication network system according to the first embodiment will be described with reference to the drawings.

  FIG. 3 is a diagram showing a femto base station selection table generation sequence in the wireless communication network system according to Embodiment 1 of the present invention. FIG. 4 is a diagram showing an example of a femto base station selection table in the wireless communication network system according to Embodiment 1 of the present invention.

  In FIG. 4, the femto base station selection table is composed of a peripheral base station list (upper limit value and lower limit value of the reception level [dBm] of the peripheral base station) for each controlled femto base station, a valid flag, and a status flag. . For example, when the control target femto base station is the femto base station 11a, the upper limit / lower limit values of the reception levels of the macro base stations 10a and 10b and the femto base station 11b are registered. The state flag represents the state of the “controlled femto base station”.

  FIG. 3 shows a table information generation sequence related to the femto base station 11a belonging to the macro base station 10a. In the operation example described below, when this sequence is performed, there is no selection table related to the femto base stations 11a and 11b in the database 60 connected to the macro base station 10a, and all the femto base stations are activated. It is in a state.

  In a state where the terminal 20 is communicating with the macro base station 10a, when the terminal 20 detects the femto base station 11a as a neighboring cell, the measurement including a cell ID related to the femto base station 11a, a reception level [dBm], and the like. The result is reported to the macro base station 10a (STEP 11).

  The macro base station 10a compares the reported measurement result of its own base station with the measurement result of the femto base station 11a, and starts the handover procedure based on the handover determination criterion. In this handover sequence, it is assumed that the X2 handover process can be performed between the macro base station and the femto base station, but the same applies to the S1 handover process via the mobility management apparatus (MME) 30. After the handover process is completed, the macro base station 10a generates a selection table illustrated in FIG. 4 using the measurement results of all the base stations reported from the terminal 20, and an effective flag indicating that the reception level has been updated. Is set (STEP 12).

  The macro base station 10a first registers the reception level registered at the time of generating the selection table as an upper limit value, and registers the reception level at the next update as a lower limit value when it is smaller than the upper limit value. If it is larger than the upper limit value, it is registered as a new upper limit value, and the first upper limit value is registered as the lower limit value. This comparison process is repeated. Further, the macro base station 10a identifies the base station type from “Closed Subscriber ID (CSG)” included in the measurement result. In addition, when the femto base station can be uniquely identified using the “Physical Cell ID” or “E-UTRAN Cell Global ID” that is the cell ID, this cell ID may be used.

  FIG. 5 is a diagram showing a femto base station suspend operation sequence in the radio communication network system according to Embodiment 1 of the present invention.

  FIG. 5 shows a sequence when the terminal 20 leaves the radio area of the femto base station 11a after the selection table related to the femto base station 11a is generated.

  When the reception level from the femto base station 11a deteriorates and the macro base station 10a is detected as a neighboring cell, the terminal 20 reports a measurement result related to the macro base station 10a to the femto base station 11a. The femto base station 11a compares the reported measurement result of its own base station with the measurement result of the macro base station 10a, and starts the handover process based on the handover determination criterion (STEP 21).

  When the measurement result of the neighboring cell is received from the terminal 20 after the handover process is completed, the macro base station 10a updates the selection table related to the femto base station 11a and sets a valid flag indicating that the reception level has been updated. . At this time, the measurement result for updating the selection table is not information on the measurement result from the terminal 20, but directly notifies the macro base station 10a of the content of the measurement result obtained by the femto base station 11a performing the handover determination. It may be done (STEP 22).

  When the femto base station 11a detects that all terminals do not exist in its own area, the femto base station 11a monitors the area of the new terminal for a certain monitoring time (STEP 23).

  If no new terminal is present during the monitoring time, the femto base station 11a notifies the macro base station 10a that the suspend state is to be entered, and the suspend state is entered. The macro base station 10a that has received this notification sets the status flag related to the femto base station 11a in the selection table to the effect that the femto base station 11a has transitioned to the suspended state. The selection table is updated (STEP 24). Note that the operation of the femto base station shifting to the suspended state is the same in the other embodiments.

  FIG. 6 is a diagram showing a femto base station activation sequence of the wireless communication network system according to the first embodiment of the present invention.

  FIG. 6 shows a sequence when the terminal 20 moves from the radio area of the macro base station 10b to the radio area of the adjacent macro base station 10a. In this state, the selection table of the femto base station 11a has already been generated, and the femto base station 11a has transitioned to the suspended state (the state flag of the selection table is set to Suspend).

  The terminal 20 located in the macro base station 10a reports the measurement results of the neighboring base stations to the macro base station 10a (STEP 31).

  The macro base station 10a receives the reception level except for the reception level in which the status flag indicating the transition to the suspended state is set out of the measurement result reported from the terminal 20 and the reception level of the selection table stored in the database 60. Is compared for each control-target femto base station, and when the selection conditions match, the femto base station 11a is instructed to resume processing. At this time, the measurement result reported from the terminal 20 does not include information on the suspended femto base station. Therefore, if the information indicating that the base station type in the selection table is a femto base station is not included in the measurement result reported from the terminal 20, the information is determined from the information of other base stations excluding that information. After instructing the resume processing of the femto base station 11a, the macro base station 10a instructs the terminal 20 to measure the femto base station 11a (STEP 32).

  Here, when the selection condition matches, the reception level of each base station reported from the terminal 20 and the reception level of each base station in the peripheral base station list of the specific control target femto base station in the selection table are respectively Specifically, when the reception level of each macro base station reported from the terminal 20 is between the upper limit value and the lower limit value of each macro base station of the selection table, and When the reception level of the femto base station is reported from the terminal 20, the reception level of each femto base station reported from the terminal 20 is between the upper limit value and the lower limit value of the reception level of each femto base station in the selection table. Is the case. On the other hand, when the reception level of the femto base station is not reported from the terminal 20, a comparison process of the reception level of the femto base station is unnecessary as a selection condition. At this time, the upper limit value and the lower limit value may be provided with hysteresis in consideration of variations in the reception level reported from the terminal.

  When the measurement result reported from the terminal 20 includes the measurement result of the femto base station 11a, the macro base station 10a recognizes that the estimation result of the resumed femto base station 11a is correct, and In the status flag related to the femto base station 11a, the fact that the femto base station 11a has shifted to the activated state is set (the status flag in the selection table is Active). Further, the macro base station 10a performs handover determination and performs handover processing to the femto base station 11a. After the handover process for the femto base station 11a is completed, the macro base station 10a updates the selection table using the measurement result from the terminal 20. At this time, if the reception level result of a specific neighboring base station is out of the threshold (upper limit / lower limit) of the reception level of each base station in the selection table, the threshold of the selection table is corrected (STEP 33).

  As for the case where the measurement result reported from the terminal 20 does not include the measurement result of the femto base station 11a, if the femto base station 11b exists as a controlled femto base station whose selection condition matches next, the femto base station Resume processing for the station 11b is performed (STEP 34). At this time, if the number of times that the measurement result reported from the terminal 20 after the resume process of the femto base station 11a does not include the measurement result of the femto base station 11a occurs more than a certain value, the reliability of the selection condition is low. In order to reconfigure the selection table, the valid flag is set to “Not Update”.

  Here, when the selection condition matches next, the reception level of each base station reported from the terminal 20 and the reception level of each base station in the peripheral base station list of a specific control target femto base station in the selection table. Specifically, the reception level of each macro base station reported from the terminal 20 is the same as that of the second table, except for the reception level of one macro base station of the selection table. When the reception level of the femto base station is reported from the terminal 20 in the case between the upper limit value and the lower limit value of the reception level of the macro base station, the reception level of each femto base station reported from the terminal 20 is This is a case between the upper limit value and the lower limit value of the reception level of each femto base station in the selection table. On the other hand, when the reception level of the femto base station is not reported from the terminal 20, a comparison process of the reception level of the femto base station is unnecessary as a selection condition.

  By performing the control based on the first embodiment, it is possible to construct a wireless communication network system that realizes power control of a corresponding femto base station only when a user (terminal) to be used exists.

Embodiment 2. FIG.
A wireless communication network system according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 7 is a diagram showing the relationship between the macro base station area and the femto base station area in the radio communication network system according to Embodiment 2 of the present invention.

  In the first embodiment, the function of controlling the power supply of the femto base station is implemented in the macro base station. In the second embodiment, these power control functions and management of the femto base station selection table are implemented in the area design operation device 4 as shown in FIG.

  Corresponding to FIG. 3, when the terminal 20 is communicating with the macro base station 10a, the terminal 20 detects the femto base station 11a belonging to the subordinate of the macro base station 10a as a neighboring base station. The measurement result including at least the cell ID and the reception level related to the base station 11a is reported to the area design operation device 4 via the macro base station 10a. The area design operation device 4 generates a femto base station selection table using the measurement results of all base stations reported from the terminal 20, and sets a valid flag indicating that the reception level has been updated.

  Corresponding to FIG. 5, when the terminal 20 moves away from the radio area of the femto base station 11a, the reception level from the femto base station 11a deteriorates and the terminal 20 uses the macro base station 10a as a neighboring base station. When detected, the measurement result including at least the cell ID and the reception level related to the macro base station 10a is reported to the area design operation device 4 via the femto base station 11a. When the femto base station 11a compares the reported measurement result of its own base station with the measurement result of the macro base station 10a and performs handover processing and detects that all terminals do not exist in its own area, Monitors the location of the new terminal for a period of time, and if the new terminal is not located, notifies the area design operation device 4 to transition to the suspended state via the macro base station 10a. Transition to the state. When the area design operation device 4 receives the measurement result of the neighboring base station from the terminal 20, the area design operation device 4 updates the femto base station selection table related to the femto base station 11a. When the notification indicating the transition to the suspended state is received from the femto base station 11a, the state flag related to the femto base station 11a in the femto base station selection table is updated in order to set the transition to the suspended state ( The status flag of the selection table is set to Suspend).

  Corresponding to FIG. 6, when the terminal 20 moves from the radio area of the macro base station 10 b to the radio area of the adjacent macro base station 10 a and the femto base station 11 a shifts to the suspended state, the terminal When 20 is located in the macro base station 10a, it reports the measurement result including at least the cell ID and reception level of the neighboring base stations to the area design operation device 4 via the macro base station 10a. The area design operation device 4 updates the reception level except for the measurement result reported from the terminal 20 and the reception level in which the status flag indicating the transition to the suspended state is set in the reception level of the femto base station selection table. The reception level in which the valid flag indicating that it has been set is compared for each femto base station, and when the two reception levels match, the resume processing is instructed to the femto base station 11a.

  In the second embodiment, the measurement result from the terminal 20 is notified to the area design operation device 4 via the macro base station and the femto base station, and there are users to be used as in the first embodiment. It is possible to construct a wireless communication network system that realizes power control of the femto base station that is applicable only to the case.

Embodiment 3 FIG.
A wireless communication network system according to Embodiment 3 of the present invention will be described with reference to FIGS.

  In the above Embodiments 1 and 2, the power control of the femto base station is performed based on the measurement results of the neighboring base stations reported from the terminal. In the third embodiment, the location probability of a femto base station that is located by location registration that starts when the terminal is located in the femto base station or wireless connection processing of a handover event is managed as the location history information of the user (terminal). Then, the femto base station to be resumed is selected from the location probability of the user location history information when the terminal is located under the macro base station to which the suspended femto base station belongs.

  FIG. 8 is a diagram showing the relationship between the macro base station area and the femto base station area in the wireless communication network system according to Embodiment 3 of the present invention.

  FIG. 8 shows the relationship between the radio areas of the macro base stations 10a and 10b and the femto base stations 11a and 11b according to the third embodiment, and the event area 70 is defined by the terminal 20 from the radio area of the macro base station 10b. When the mobile station moves to the wireless area of the adjacent macro base station 10a, the event area 71 is an area in which wireless connection processing for location registration or handover event occurs. The terminal area 20 is located under the macro base station 10a from the wireless area of the macro base station 10a. This is an area where location registration and handover event wireless connection processing occur when moving to the wireless area of the femto base station 11a to which it belongs.

  FIG. 9 is a diagram showing a position registration sequence when the terminal of the wireless communication network system according to Embodiment 3 of the present invention is in the femto base localized area. FIG. 10 is a diagram showing an example of user location history information of the wireless communication network system according to Embodiment 3 of the present invention.

  In FIG. 10, the user location history information is composed of a location probability and a status flag for each femto base station associated with the user ID. This state flag represents the state of the femto base station managed by the “femto base station ID”.

  FIG. 9 shows a location registration sequence when the terminal 20 is located in the femto base station 11a. In the operation example described below, when this sequence is executed, there is no user location history information in the database 60 connected to the area design operation device 4, and all femto base stations are activated. It is.

  After the terminal 20 located in the macro base station 10a detects the femto base station 11a, the terminal 20 is located in the femto base station 11a by celery selection evaluation. After recognizing the change of the location registration area by the notification information of the femto base station 11a in the event area 71, the terminal 20 starts the location registration process to the wireless communication network (STEP 41).

  In this sequence, when the authentication process is performed between the terminal 20 and the mobility management apparatus (MME) 30 and the terminal 20 is authenticated as a normal user, the mobility management apparatus (MME) 30 generates user information. As shown in FIG. 10, the user information includes a user ID, a visited macro base station ID, and a femto base station ID. As the user ID, an identifier such as an IMSI (International Mobile Subscriber Identity) registered in the USIM card that can uniquely identify the user is used. For the macro base station ID and the femto base station ID, an identifier capable of uniquely identifying the base station such as an ECGI (E-UTRAN Cell Global ID) capable of uniquely identifying the cell is used (STEP 42).

  The mobility management device (MME) 30 that has generated the user information notifies the area design operation device 4 of user information including base station information in which the terminal 20 is located. Upon receiving this notification, the area design operation device 4 registers the received user information in the database 60 as user location history information associated with the user ID, and updates the calculation result of the location probability. The area design operation device 4 counts notification of user information corresponding to location registration as the number of communication attempts for each femto base station. The location probability is obtained from location probability (%) = ((number of communication trials at a specific femto base station) / (number of communication trials at all femto base stations under the macro base station)) × 100. By this processing, user location history information is generated in the database 60 connected to the area design operation device 4 (STEP 43).

  Although the above processing shows an example of location registration as an event, the same applies to the handover processing.

  FIG. 11 is a diagram showing a femto base station activation sequence of the wireless communication network system according to the third embodiment of the present invention.

  FIG. 11 shows a sequence when the terminal 20 moves from the radio area of the macro base station 10b to the radio area of the adjacent macro base station 10a. In this state, the user location history information of the terminal 20 is generated in the database 60 connected to the area design operation device 4, and the femto base station 11a having the highest location probability is shifted to the suspended state. Yes.

  After the terminal 20 recognizes the change of the location registration area by the notification information of the macro base station 10a in the event area 70, the location registration process to the wireless communication network is started (STEP 51).

  Similar to when the user location history is generated, the mobility management device (MME) 30 generates user information upon authenticating that the terminal 20 is a normal user, and includes macro base station information where the terminal 20 is located. The user information is notified to the area design operation device 4 (STEP 52).

  The area design operation device 4 that has received this notification selects the femto base station 11a that is the femto base station with the highest location probability from the user location history information. After the area design operation device 4 executes the resume processing (femto base station activation notification) of the femto base station 11a (STEP 53), the macro base station 10a instructs the terminal 20 to measure the femto base station 11a (STEP 54).

  When the measurement result reported from the terminal 20 includes the measurement result of the femto base station 11a, the macro base station 10a recognizes that the estimated result of the resumed femto base station 11a is correct, and performs handover determination. Handover processing to the femto base station 11a is performed. After the handover process for the femto base station 11a is completed, the area design operation device 4 updates the user location history information (location probability) of the terminal 20 (STEP 55).

  When the measurement result reported from the terminal 20 does not include the measurement result of the femto base station 11a, a resume process is performed on the femto base station with the next highest probability of being in the area. At this time, the suspend process may be performed again on the femto base station 11a.

  By performing the control based on the third embodiment, a radio communication network system that realizes power control of the corresponding femto base station only when there is a user (terminal) having a high probability of using the femto base station is constructed. It becomes possible.

Embodiment 4 FIG.
A wireless communication network system according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 12 is a diagram showing a periodic activation operation of the femto base station in the wireless communication network system according to the fourth embodiment of the present invention.

  In the first, second, and third embodiments described above, when there is a user (terminal) that uses the femto base station, power control of the femto base station is performed. However, in a specific place where users (terminals) around the femto base station frequently enter and leave the wireless area 50, the control complexity increases by performing power supply control based on measurement information from individual terminals. To do. Therefore, in the fourth embodiment, periodic autonomous power control by the femto base station is performed at a specific place where a user (terminal) frequently enters and exits in the corresponding femto base station area.

  When the terminal 20 ends the communication with the femto base station, the femto base station starts periodic power control. The cycle (light sleep interval) for shifting to the short-time suspend state may be a fixed cycle, or the cycle may be reduced at regular intervals as shown in FIG. In this cycle, the probability that the femto base station detects the terminal 20 is collected by the area design operation device 4 so that the power control cycle according to the user characteristics of the place where the femto base station is installed can be determined. Become.

  That is, the communication request from the terminal 20 is monitored for a certain period of time by showing the femto base station area to the terminal 20 in a section where the femto base station is autonomously activated periodically. Thereby, the femto base station realizes the location check of the terminal 20 that requests communication. When the terminal 20 does not start communication with the femto base station for a certain period of time, the femto base station determines that there is no terminal 20 requesting communication around the femto base station, and suspends for a longer time than the light sleep period. Move to (Deep Sleep).

  After that, the femto base station starts up autonomously from the long-time suspend state (deep sleep period) and restarts power control that periodically shifts to the short-time suspend state (light sleep period). A femto base station installed at a specific place where a user (terminal) frequently enters and exits within the own station area periodically shifts to a short suspend state until the terminal 20 starts communication with the own station. Periodic autonomous power control is repeatedly executed in the sleep period and in the deep sleep period in which the state transitions to the suspended state for a longer time than the light sleep period.

  By performing the control based on the fourth embodiment, the femto base station has a power source for the femto base station when there is no user (terminal) requesting communication even in an environment where the user (terminal) frequently enters and exits. It is possible to construct a wireless communication network system that can realize control.

  DESCRIPTION OF SYMBOLS 1 Radio access network (E-UTRAN), 2 UE (User Equipment), 3 core network (EPC: Evolved Packet Core), 4 area design operation apparatus, 5 HeNB-GW (Home eNodeB Gateway), 10a, 10b Macro base station 11a, 11b Femto base station, 20 terminals, 40 macro base station area, 50 femto base station area, 60 database, 70 event area, 71 event area.

Claims (3)

Multiple macro base stations;
A plurality of femto base stations belonging to each macro base station,
A plurality of terminals that communicate with each macro base station and each femto base station;
A wireless communication network system comprising a database storing a femto base station selection table composed of reception levels, valid flags and status flags of neighboring base stations for each femto base station to be controlled,
When the first terminal is communicating with the first macro base station,
When the first terminal detects the first femto base station belonging to the first macro base station as a neighboring base station, the measurement result includes at least a cell ID and a reception level related to the first femto base station. To the first macro base station,
The first macro base station compares the reported measurement result of its own base station with the measurement result of the first femto base station, performs a handover process, and after completing the handover process, Using the measurement results of all the base stations reported from the terminal, generate the femto base station selection table, and set a valid flag indicating that the reception level has been updated,
When the first terminal is away from the radio area of the first femto base station,
When the reception level from the first femto base station deteriorates and the first terminal detects the first macro base station as a neighboring base station, the first terminal detects a cell ID and a reception level related to the first macro base station. To the first femto base station a measurement result including at least
The first femto base station compares the reported measurement result of its own base station with the measurement result of the first macro base station and performs handover processing, and confirms that all terminals are not present in its own area. When detected, the area of the new terminal is monitored for a certain monitoring time, and if the new terminal does not exist, the first macro base station is notified of the transition to the suspended state, and suspended. Transition to the state,
When the first macro base station receives a measurement result of a neighboring base station from the first terminal after completing the handover process, the first macro base station updates a femto base station selection table related to the first femto base station. When the effective flag indicating that the reception level has been updated is set and the notification indicating the transition to the suspended state is received from the first femto base station, the first femto base station in the femto base station selection table is notified. Update the femto base selection table associated with the first femto base station to set the associated status flag to indicate that it has transitioned to the suspended state ;
When the first terminal has moved from the radio area of the second macro base station to the radio area of the adjacent first macro base station, and the first femto base station has transitioned to the suspended state Is
When the first terminal is located in the first macro base station, the first terminal reports a measurement result including at least a cell ID of a neighboring base station and a reception level to the first macro base station,
The first macro base station uses a reception level in which a status flag indicating that a transition has been made to a suspended state is set among the measurement result reported from the first terminal and the reception level of the femto base station selection table. Except for this, the reception level in which the valid flag indicating that the reception level has been updated is compared for each femto base station, and when the two reception levels match, the resume processing is instructed to the first femto base station. A wireless communication network system. Multiple macro base stations;
A plurality of femto base stations belonging to each macro base station,
A plurality of terminals that communicate with each macro base station and each femto base station;
Area design operation device for managing and changing radio parameters of each macro base station and each femto base station;
A wireless communication network system comprising a database storing a femto base station selection table composed of reception levels, valid flags and status flags of neighboring base stations for each femto base station to be controlled,
When the first terminal is communicating with the first macro base station,
When the first terminal detects the first femto base station belonging to the first macro base station as a neighboring base station, the measurement result includes at least a cell ID and a reception level related to the first femto base station. To the area design operation device via the first macro base station,
The area design operation device uses the measurement results of all base stations reported from the first terminal, generates the femto base station selection table, sets a valid flag indicating that the reception level has been updated,
When the first terminal is away from the radio area of the first femto base station,
When the reception level from the first femto base station deteriorates and the first terminal detects the first macro base station as a neighboring base station, the first terminal detects a cell ID and a reception level related to the first macro base station. To the area design operation device via the first femto base station,
The first femto base station compares the reported measurement result of its own base station with the measurement result of the first macro base station and performs handover processing, and confirms that all terminals are not present in its own area. When detected, the area of the new terminal is monitored for a certain monitoring time, and if the new terminal is not in the area, the area design operation apparatus is suspended through the first macro base station. To transition to suspend state,
When the area design operation device receives the measurement result of the neighboring base station from the first terminal, the area design operation device updates the femto base station selection table related to the first femto base station, and receives the measurement result from the first femto base station. When the notification of transition to the suspend state is received, the first femto base is set to set the state flag related to the first femto base station in the femto base station selection table to the transition to the suspend state. Update the femto base selection table associated with the station ,
When the first terminal has moved from the radio area of the second macro base station to the radio area of the adjacent first macro base station, and the first femto base station has transitioned to the suspended state Is
When the first terminal is located in the first macro base station, the area design includes a measurement result including at least a cell ID of a neighboring base station and a reception level via the first macro base station. Report to operational equipment,
The area design operation device, except for the measurement result reported from the first terminal and the reception level in which the status flag indicating the transition to the suspended state is set among the reception levels of the femto base station selection table, The reception level set with the valid flag indicating that the reception level has been updated is compared for each femto base station, and when both reception levels match, the resume processing is instructed to the first femto base station. A featured wireless communication network system. Multiple macro base stations;
A plurality of femto base stations belonging to each macro base station,
A plurality of terminals that communicate with each macro base station and each femto base station;
A mobility management device for managing the mobility of the terminal;
Area design operation device for managing and changing radio parameters of each macro base station and each femto base station;
A wireless communication network system comprising: a database for storing user location history information configured from the location probability for each femto base station associated with a user ID,
When the first terminal moves from the first macro base station to the first femto base station belonging to the first macro base station,
The first terminal performs wireless connection processing according to broadcast information of the first femto base station,
The mobility management device performs authentication processing with the first terminal according to the wireless connection processing, and authenticates that the first terminal is a normal user, generates user information and Notify the area design operation device,
The area design operation device that has received the notification registers the user information in the database as user location history information associated with a user ID, and notifies the user information corresponding to the wireless connection process as the number of communication attempts. Count for each femto base station, and update the calculation result of the location probability that is the ratio of the number of communication attempts at all femto base stations under the macro base station and the number of communication attempts at a specific femto base station for each femto base station. ,
When the first terminal moves from the radio area of the second macro base station to the radio area of the adjacent first macro base station, the first femto base station having the highest location probability is in the suspended state If you are transitioning to
The first terminal performs wireless connection processing according to the broadcast information of the first macro base station,
The mobility management device performs authentication processing with the first terminal according to the wireless connection processing, and authenticates that the first terminal is a normal user, generates user information and Notify the area design operation device,
The area design operation device that has received the notification selects the first femto base station with the highest probability of being located from the user location history information registered in the database, and A wireless communication network system characterized by instructing resume processing.

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