JP2015220715A - Mobile communication system, base station control device, base station control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To start the optimal base station under the consideration of a user's physical feeling such as throughput in the case of starting a base station in a stop state.SOLUTION: The mobile communication system is configured to receive first load information from each of a plurality of base stations and UE measurement information from a user terminal, and to, when determining that a user terminal which does not satisfy service quality is present from the received information, select the base station in a stop state in the periphery of the connection cell of the user terminal as a start candidate, and to acquire second load information by predicting the estimated radio quality information of each cell to be measured by a user terminal in the case of starting the start candidate and the change of the connection cell of the user terminal, and to, on the basis of the estimated radio quality information and the first and second load information, calculate the estimation value of the service quality of the user terminal after the starting the start candidate, and to, on the basis of the calculated service quality estimation value, select the base station to be started from among the start candidates, and to notify the selected base station of a start instruction to shift the stop state to the start state.

Description

  The present invention relates to a mobile communication system, a base station control device, a base station control method, and a program, and in particular, a mobile communication system, a base station control device, a base station control method, and a program for starting a dormant base station with power saving control About.

  With the spread of smartphones and tablet terminals, data traffic of mobile communication has increased rapidly, and in recent years, LTE (Long Term Evolution) communication that achieves high speed and large capacity has been spread. In applications such as music and video streaming, a communication speed (throughput) of 1 Mbps or more is required.

  In order to cope with this rapid increase in data traffic, the number of installed radio base stations (hereinafter referred to as base stations) is also expected to increase. Specifically, large macro base stations with large transmission power and wide communication area are installed, and small base stations with small transmission power and small communication area are placed on commercial facilities and highways with many users. A wireless access network configuration is expected. In this wireless access network form, macro base stations ensure coverage (communication range), and then small base stations are spotted in areas with high traffic demand, enabling efficient mobile network capacity. Can be realized.

  A wireless access network configuration in which base stations in various communication areas are mixed is called a heterogeneous network. Moreover, although the said communication area is called a cell, the base station can also manage a some cell by giving directivity to an antenna.

  The mobile communication system is composed of a core network, a radio access network mainly composed of base stations, and user terminals (hereinafter referred to as UEs and User Equipments). And 70 to 80% of the power of the mobile communication system is consumed in the radio access network. Therefore, as the number of base stations increases in response to the rapid increase in data traffic, the power consumption also increases rapidly. Therefore, it is extremely difficult to reduce the power consumption of the radio access network from the viewpoint of reducing operational costs and environmental load. It becomes an important issue.

  An effective method for reducing the power consumption of the radio access network is to put the entire base station function or a part of the base station function into a dormant state, thereby greatly reducing the power consumption of the base station.

  Techniques for reducing the power consumption of the radio access network are disclosed in the following patent documents.

  Patent Document 1 discloses a technique for maintaining a minimum number or a minimum number of operating base stations necessary to satisfy current traffic demand in a radio access network. According to this technique, the load in a predetermined base station section is monitored, and in the case of an overload, the presence or absence of an adjacent section that is not overloaded is confirmed. When there is an adjacent section that is not overloaded, the pilot channel power of the operating base station is reset including the adjacent section without starting the inactive base station, and the energy partition is reconfigured. Is called. In addition, when there is no adjacent section that is not overloaded, the base station that is dormant in the overloaded section is activated. A dormant base station activated in this overload section is selected based on a simple geographical relationship with a heavily loaded base station.

  In Patent Document 2, when there is no UE using the base station, the base station is shifted to the sleep mode, and when the UE close to the base station transmits a wake-up command, the base station is immediately activated ( wake-up) is disclosed. The base station performs paging in the coverage area, and determines that there is no UE using the base station when detecting no response to paging. Also, the UE that is close to the base station detects fingerprint, which is arbitrary information such as the cell number of a cell seen in the vicinity and GPS (Global Positioning System) information, and transmits a wake-up command.

Special table 2013-509761 gazette International Publication No. 2010/151186

  In order to maintain the user experience such as throughput and transmission delay for communicating users, even if the base station has been stopped for power saving, the base station has been put into a dormant state according to the UE movement status. It is necessary to start the station appropriately.

  The technique disclosed in Patent Document 1 focuses on maintaining the minimum number or as few as possible operating base stations to satisfy traffic demand. For this reason, no mention is made of maintaining the user experience for the communicating user.

  On the other hand, the technique disclosed in Patent Literature 2 activates a dormant base station by detecting a so-called fingerprint and transmitting a wake-up command by a UE that has approached the dormant base station. From this point of view, the technique disclosed in Patent Document 2 can appropriately activate a dormant base station according to the movement status of the UE. However, this technique starts the dormant base station as soon as the UE approaches the dormant base station without considering the user experience. Therefore, depending on the situation, a base station that does not need to be activated is activated, and there is a problem in terms of maintaining power consumption and user experience.

  FIG. 16 is a conceptual diagram illustrating a problem in the technique disclosed in Patent Document 2.

  Two tasks (task 1 and task 2) are shown in the upper and lower portions of the figure.

  The problem 1 shown in the upper part of the figure is that when the technique disclosed in Patent Document 2 is used, the base station is started uselessly even though there is no problem in terms of the user experience, and the power consumption increases. It is a problem that it ends up.

  Further, Problem 2 shown in the lower part of the figure is a problem that a base station that can further improve the user experience cannot be activated when the technique disclosed in Patent Document 2 is used.

  Here, the user experience is described as the throughput of the UE. Further, it is assumed that a throughput of 1 Mbps or more is a requirement standard for the user experience.

  In FIG. 16, base stations N1 to N4 are illustrated as base stations constituting the radio access network. Of these, it is assumed that the base stations N1 and N2 are active and the base stations N3 and N4 are inactive.

  Problem 1 will be described.

  If a new UE 3 to be connected to the base station is generated near the boundary between the base station N2 and the base station N3, according to the technique of Patent Document 2, the new UE 3 is suspended as shown in the left diagram at the top of FIG. The middle base station N3 is activated. At this time, the new UE 3 can start the base station N3 and communicate at a throughput of 7 Mbps.

  However, in this case, as shown in the diagram on the right side in the upper part of FIG. 16, the new UE 3 can communicate with the operating base station N2 at a throughput of 4 Mbps without starting the base station N3. Suppose. That is, the new UE 3 activates the base station N3 and increases power consumption even though it can achieve a user throughput larger than the required standard of 1 Mbps with the base station N2.

  Problem 2 will be described.

  Assuming that a new UE 5 is generated near the boundary between the base station N2, the base station N3, and the base station 4, according to the technique of Patent Document 2, as shown in the left diagram at the bottom of FIG. Start station N3. At this time, the new UE 5 can start the base station N3 and communicate at a throughput of 5 Mbps. However, the operating base station N2 is in a high load state, and the UE 3 existing in the vicinity of the boundary between the base station N2 and the base station 4 is communicating at 1 Mbps, which is just below the required standard.

  In this case, as shown in the diagram on the right side at the bottom of FIG. 16, if the base station N4 is activated, the new UE 5 can communicate with the base station N4 at a throughput of 4 Mbps due to the effect of load balancing, and the UE 3 Can be improved to 2 Mbps.

  The present invention has been made in view of the above problems. An object of the present invention is to provide a mobile communication system, a base station control device, and a base that can activate an optimal dormant base station in consideration of a user experience such as throughput and can prevent an unnecessary increase in power consumption A station control method and program are provided.

  In order to achieve the above object, a base station control apparatus according to one aspect of the present invention uses, as a connected cell, a cell managed by the base station from each of a plurality of base stations arranged in a predetermined area. UE including first load information of the base station including an actual value of service quality of the user terminal, location information reported by the user terminal to the base station, and radio quality information of each cell measured at the location (User Equipment) If there is the user terminal that has received measurement information and does not satisfy a predetermined quality of service, a dormant base that can manage the neighboring cells of the connected cell of the user terminal that does not satisfy the quality of service An activation base station selection means for selecting a station as an activation base station candidate, and estimation of radio quality information of each cell measured by the user terminal when the activation base station candidate is activated The second load information of each of the activated base stations after the activation base station candidate is activated by predicting a change in the connected cell of the user terminal based on the estimated radio quality information. Based on the acquired radio quality information calculating means, the estimated radio quality information, the first load information, and the second load information, the service quality of the user terminal after the activation base station candidate is activated is estimated. Service quality calculation means for calculating a value as a service quality estimation value, and the activation base station selection means is a base station to activate any of the activation base station candidates based on the service quality estimation value It is characterized by notifying the selected base station of an activation instruction for transitioning from an inactive state to an activated state.

  A mobile communication system according to another embodiment of the present invention includes a plurality of base stations arranged in a predetermined area and a base station control device that controls the plurality of base stations, and the base station control device Is the base station control device described above, wherein each of the plurality of base stations includes a load of the base station including an actual service quality measurement value of a user terminal having a cell managed by the base station as a connection cell. A base station operation means for reporting the UE measurement information reported by the user terminal to the base station control device, and receiving a notification of the activation instruction from the base station control device, the predetermined device operation being suspended Activation control means for activation.

  In addition, a base station control method according to another aspect of the present invention provides a service quality of a user terminal that uses a cell managed by the base station as a connected cell from each of a plurality of base stations arranged in a predetermined area. UE (User Equipment) measurement information including first load information of the base station including an actual measurement value, location information and radio quality information of each cell measured at the location, reported to the base station by the user terminal. And determining whether there is the user terminal that does not satisfy the predetermined service quality, and determining that there is the user terminal that does not satisfy the service quality, the service quality that does not satisfy the service quality Measured by the user terminal when a dormant base station that can manage neighboring cells of a connected cell of the user terminal is selected as a starting base station candidate and the starting base station candidate is started. Estimating radio quality information of each cell as estimated radio quality information, predicting a change in the connected cell of the user terminal based on the estimated radio quality information, and starting the activated base station candidate The second load information of each of the stations, and based on the estimated radio quality information, the first load information, and the second load information, the user terminal after starting the start base station candidate An estimated service quality value is calculated as a service quality estimate value, and based on the service quality estimate value, one of the activated base station candidates is selected as a base station to be activated, and the selected base station is in a dormant state It is characterized by notifying of an activation instruction to shift to an activated state from

  Furthermore, a program according to another aspect of the present invention is a program for improving the quality of service of a user terminal that uses a cell managed by a base station from each of a plurality of base stations deployed in a predetermined area as a connected cell. UE (User Equipment) measurement information including first load information of the base station including an actual measurement value, location information and radio quality information of each cell measured at the location, reported to the base station by the user terminal. The service quality determination function means for determining the presence or absence of the user terminal that does not satisfy the predetermined service quality, and the service quality determination function means that there is the user terminal that does not satisfy the service quality. If it is determined, a base station that is inactive that can manage neighboring cells of the connected cell of the user terminal that does not satisfy the service quality An activation base station candidate selection function means to select the estimated radio quality information, estimated radio quality information of each cell measured by the user terminal when the activation base station candidate is activated, and the estimated radio quality information Radio quality information calculation function means for predicting a change in the connected cell of the user terminal based on the base station and obtaining second load information of each active base station after starting the active base station candidate; Based on the estimated radio quality information, the first load information, and the second load information, a service quality estimate value of the user terminal after starting the activation base station candidate is calculated as a service quality estimate value. Service quality calculation function means and any one of the activated base station candidates are selected as base stations to be activated on the basis of the service quality estimation values, and the selected base station is suspended. It is a program for functioning as a base station activation notification function means for notifying an activation instruction for shifting to an activation state.

  The present invention can start an optimal dormant base station in consideration of a user experience based on service quality, and can prevent an unnecessary increase in power consumption.

It is a block diagram which shows the structure of the mobile communication system of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the base station control apparatus of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the base station of the 1st Embodiment of this invention. It is a flowchart which shows the flow of a process of the base station control method of the 1st Embodiment of this invention. It is a block diagram which shows the hardware constitutions of the base station control apparatus of the 1st Embodiment of this invention. It is a figure which shows the structure of the function means which the program of the 1st Embodiment of this invention implement | achieves. It is a block diagram which shows the structure of the mobile communication system of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the base station control apparatus of the 2nd Embodiment of this invention. It is a figure which shows the example of data registered into UE measurement information database. It is a flowchart which shows operation | movement of the base station control apparatus of the 2nd Embodiment of this invention. It is a flowchart which shows the modification of operation | movement of the base station control apparatus of the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the base station of the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the base station control apparatus of the 3rd Embodiment of this invention. It is a block diagram which shows the structure of the mobile communication system of the 4th Embodiment of this invention. It is a block diagram which shows the structure of the main base station of the 4th Embodiment of this invention. It is a conceptual diagram explaining the subject used as the background of this invention.

  DESCRIPTION OF EMBODIMENTS Embodiments for carrying out the present invention will be described with reference to the drawings.

  The embodiments are examples, and the disclosed apparatus and system are not limited to the configurations of the following embodiments.

  FIG. 1 is a block diagram showing the configuration of the mobile communication system 1 according to the first embodiment of the present invention.

  Referring to FIG. 1, a mobile communication system 1 according to the present embodiment includes a base station control device 10, a plurality of base stations 20-1 to 20-4 and user terminals (UE) 40-1 arranged in a predetermined area. Thru | or 40-3 are comprised. Base stations 20-1 to 20-4 form wireless cells (hereinafter referred to as cells) 30-1 to 30-4, which are communication areas.

  Here, it is assumed that the base stations 20-1 and 20-2 indicated by solid lines are activated and the base stations 20-3 and 20-4 indicated by dotted lines are inactive.

  In the following description, when a base station, a UE, or a cell is described as a generic term, it is referred to as a base station 20, a UE 40, or a cell 30, and when a base station, a UE, or a cell is specified and described, It shall be referred to as 20-x, UE 40-x or cell 30-x.

  The UE 40 reports UE (User Equipment) measurement information including location information and radio quality information of each cell measured at the location to the base station 20 that manages the connected cell of the UE 40. For example, the UE 40-1 reports the current location information of the UE 40-1 and the radio quality information of the cell 30-1 and the cell 30-2 received at the location to the base station 20-1.

  The base station 20 controls the base station 20 with the load information of the base station 20 including the actual measurement value of the service quality of the UE 40 using the cell 30 managed by the base station 20 as the connection cell, and the UE measurement information reported from each UE 40. Transmit to device 10. For example, the base station 20-1 measures the service quality of the UE 40-1, and loads the load information of the base station 20-1 including the actual measurement value and the UE measurement information reported by the UE 40-1 into the base station controller 10. Send to. Needless to say, the service quality and UE measurement information of another UE 40 (not shown) that uses the cell 30 managed by the base station 20-1 as the connected cell are also transmitted to the base station control device 10.

  Here, in order to distinguish the load information transmitted from each base station 20 to the base station control apparatus 10 from the load information of each base station 20 assumed when a dormant base station described later is started, Referred to as load information. As will be described later, the load information of each base station 20 assumed when a dormant base station is activated is referred to as second load information.

  When the base station control device 10 performs control to be described later and decides to activate the base station 20 that is in a suspended state, the base station control device 10 selects the activation base station candidate as the activation candidate, and from the activation base station candidate The base station 20 to be activated is selected. Then, the activation instruction is notified to the base station 20 selected as the activation target. For example, the base station controller 10 selects the dormant base station 20-3 and the base station 20-4 as activation base station candidates, and selects the dormant base station 20-3 as the activation target base station 20. Suppose that In this case, the base station control device 10 notifies the start instruction to the base station 20-3.

  First, the configuration of the base station control apparatus 10 will be described with reference to FIG.

  FIG. 2 is a block diagram illustrating a configuration of the base station control device 10 according to the first embodiment of this invention.

  The base station control device 10 is configured to include an activated base station selection unit 11, a radio quality information calculation unit 12, and a service quality calculation unit 13.

  The starting base station selection means 11 receives the first load information of the base station 20 and the UE reported to the base station 20 from each of the plurality of base stations 20 arranged in a predetermined area. Receive measurement information. Then, if there is a UE 40 that does not satisfy the predetermined quality of service, the activated base station selection unit 11 selects a base station 20 that is inactive that can manage the neighboring cells of the connected cell of the UE 40 that does not satisfy the quality of service. Select as a starting base station candidate.

  Further, the activation base station selection unit 11 selects one of the activation base station candidates as the base station 20 to be activated based on the service quality estimation value calculated by the service quality calculation unit 13 as described later. Then, the activated base station selection unit 11 notifies the selected base station 20 of an activation instruction for shifting from the sleep state to the activated state.

  The radio quality information calculation means 12 estimates the radio quality information of each cell measured by the UE 40 as the estimated radio quality information when the activated base station candidate is activated. Then, the radio quality information calculation unit 12 predicts the change of the connected cell of the UE 40 based on the estimated radio quality information, and obtains each load information of the activated base station 20 after starting the activated base station candidate. Obtained as the second load information described above.

  The service quality calculation means 13 calculates an estimated value of the service quality of the UE 40 after starting the activation base station candidate as a service quality estimated value based on the estimated radio quality information, the first load information, and the second load information. To do.

  Next, the configuration of the base station 20 will be described with reference to FIG.

  FIG. 3 is a block diagram illustrating a configuration of the base station 20 according to the first embodiment.

  The base station 20 is configured to include a base station operation unit 201 and an activation control unit 202.

  The base station operation unit 201 reports the load information (first load information) of the base station 20 including the actual measured value of the service quality of the UE 40 using the cell 30 managed by the base station 20 as a connected cell, and the UE 40 reports The UE measurement information is reported to the base station controller 10.

  When the activation control unit 202 receives the activation instruction notification from the base station control device 10, the activation control unit 202 activates a predetermined apparatus operation during suspension.

  Next, the base station control method of the first embodiment will be described.

  FIG. 4 is a flowchart showing a process flow of the base station control method according to the first embodiment.

  First, from each of a plurality of base stations 20 deployed in a predetermined area, a first value of the base station 20 including an actual service quality measurement value of the UE 40 using the cell 30 managed by the base station 20 as a connection cell. The load information and the UE measurement information reported to the base station 20 by the UE 40 are received. And the presence or absence of UE40 which is not satisfying predetermined service quality is determined (S101).

  When it is determined that there is a UE 40 that does not satisfy the service quality, the dormant base station 20 that can manage the neighboring cells of the connected cell of the UE 40 that does not satisfy the service quality is selected as a starting base station candidate (S102). ).

  When the activation base station candidate is activated, the radio quality information of each cell measured by the UE 40 is estimated as estimated radio quality information. Then, a change in the connected cell of the UE 40 is predicted based on the estimated radio quality information, and each piece of load information of the activated base station after the activated base station candidate is activated is acquired as second load information ( S103).

  Based on the estimated radio quality information, the first load information, and the second load information, an estimated value of the service quality of the UE 40 after activation of the activated base station candidate is calculated as a service quality estimated value (S104).

  Based on the calculated service quality estimation value, one of the activated base station candidates is selected as the base station 20 to be activated, and the selected base station 20 is notified of an activation instruction for shifting from an idle state to an activated state ( S105).

  Next, the program of the first embodiment will be described.

  FIG. 5 is a block diagram illustrating a hardware configuration of the base station control device 10 according to the first embodiment.

  Referring to FIG. 5, the base station control device 10 can be realized by a hardware configuration similar to that of a general computer device, and includes the following configuration.

  The hardware configuration includes a CPU (Central Processing Unit) 31, a main storage unit 32, and an auxiliary storage unit 33 that are control units. The main storage unit 32 is configured by a RAM (Random Access Memory) or the like, and the auxiliary storage unit 33 includes a hard disk device including a nonvolatile memory such as a magnetic disk or a semiconductor memory.

  The hardware configuration includes a communication control unit 34 that transmits and receives data via a network, a display unit 35 using a display, an input unit 36 that performs key operations, a system bus 37 that interconnects the above-described components, and the like. .

  The base station control device 10 of the present embodiment is implemented by mounting circuit components composed of hardware components such as LSI (Large Scale Integration) in which a program for realizing each function is incorporated in the base station control device 10. May be realized. Further, the base station control device 10 of the present embodiment may be realized in software by executing a program that provides each function of each component by the CPU 31 on the computer processing device.

  That is, the CPU 31 loads the program stored in the auxiliary storage unit 33 to the main storage unit 32 and executes it, or directly executes it on the auxiliary storage unit 33 to control the operation of the base station control device 10. Thus, each function is realized by software.

  FIG. 6 shows a configuration of functional means realized by the program according to the first embodiment of the present invention.

  The program according to the present embodiment functions as a service quality determination function unit 301, an activated base station candidate selection function unit 302, a radio quality information calculation function unit 303, a service quality calculation function unit 304, and a base station activation notification function unit 305. Let

  The service quality determination function unit 301 includes, from each of a plurality of base stations 20 deployed in a predetermined area, a first value of the base station 20 that includes an actual service quality measurement value of the UE 40 using the base station 20 as a connection cell. Load information and UE measurement information reported to the base station 20 by the UE 40. And the presence or absence of UE40 which is not satisfying predetermined service quality is determined.

  If it is determined that there is a UE 40 that does not satisfy the service quality, the activated base station candidate selection function unit 302 can manage the neighboring cells of the connected cell of the UE 40 that does not satisfy the service quality. Are selected as starting base station candidates.

  The radio quality information calculation function unit 303 estimates the radio quality information of each cell measured by the UE 40 as estimated radio quality information when the activated base station candidate is activated. Then, a change in the connected cell of the UE 40 is predicted based on the estimated radio quality information, and each load information of the activated base station 20 after the activated base station candidate is activated is acquired as second load information. .

  Based on the estimated radio quality information, the first load information, and the second load information, the service quality calculation function unit 304 uses the estimated service quality value of the UE 40 after activating the activated base station candidate as the service quality estimated value. calculate.

  The base station activation notifying function unit 305 selects one of the activated base station candidates as the base station 20 to be activated based on the calculated service quality estimation value, and activates the selected base station 20 from the inactive state. Notify the start instruction to shift to the state.

  As described above, in the present embodiment, when there is a UE 40 that does not satisfy the service quality, the service quality estimation value in each UE 40 when the dormant base station 20 is activated is calculated, and It is possible to determine which of the base stations 20 should be activated. Therefore, an optimal dormant base station can be activated in consideration of the user experience based on service quality, and an unnecessary increase in power consumption can be prevented.

  Next, a second embodiment will be described.

  First, the configuration will be described.

  FIG. 7 is a block diagram illustrating a configuration of the mobile communication system 2 according to the second embodiment of this invention. In the present embodiment, LTE will be described as an example of the mobile communication system 2.

  FIG. 7 is different only in that the base station control device 10 of the mobile communication system 1 of the first embodiment described with reference to FIG. Therefore, the base station control device 10 described in the mobile communication system 1 of the first embodiment may be read as the base station control device 100.

  As an additional explanation, the base station 20-1 is a macro base station, and forms the cell 30-1, and the base stations 20-2 to 20 as spot small base stations in areas where there is a high traffic demand. -4 is arranged. That is, the cells 30-2 to 30-4 formed by the base stations 20-2 to 20-4 that are small base stations are included in the cell 30-1.

  The base station control device 100 acquires UE measurement information and load information of each cell from the activated base stations 20-1 and 20-2, and performs activation control of the dormant base stations 20-3 and 20-4. To do.

  If the base station 20 is in the activated state, the base station 20 manages the cell 30 (hereinafter, this cell is referred to as its own cell), and performs bidirectional communication with the connected UE 40. Further, the base station 20 measures the load of the own cell (first load information) and reports it to the base station control apparatus 100.

  Although not shown, the base station 20 is connected to an upper network such as a core network and relays traffic communication between the UE 40 and the upper network if it is in an activated state. Moreover, the base station 20 will acquire UE measurement information from UE40, if it is a start-up state.

  In the present embodiment, the UE measurement information includes RSRP (Reference Signal Received Power) and location information.

  RSRP is a reception strength of the reference signal transmitted by each base station 20 at the UE 40, and is one of general reception strength indicators called UEmeasurement in LTE.

  As a method for acquiring the position information, for example, it is conceivable to use MDT (Minimization of Drive Tests) standardized by 3GPP (Thrid Generation Partnership Project). Conventionally, the MDT automatically collects the signal strength measurement of each base station 20 that has been performed by a carrier by a drive test or the like by using the UE 40 in order to optimize the coverage of the base station 20. It is a mechanism. By using MDT, man-hours and costs can be reduced compared to a drive test in which service quality is confirmed by moving within a service area. As another method for acquiring position information, a method for reading position information acquired by an application such as a smartphone may be used.

  The UE 40 reports the above-described UE measurement information based on an instruction from the connected base station 20.

  Next, the configuration of the base station control apparatus 100 will be described.

  FIG. 8 is a block diagram illustrating a configuration example of the base station control device 100 according to the second embodiment. The base station control device 100 is configured to include an activated base station selection unit 101, a radio quality information calculation unit 102, a service quality calculation unit 103, and a UE measurement information database 104. The activation base station selection unit 101, the radio quality information calculation unit 102, and the service quality calculation unit 103 are the activation base station selection unit 11, the radio quality information calculation unit 12, and the service quality calculation of the base station control apparatus 10 according to the first embodiment. Each corresponds to the means 13. The UE measurement information database 104 is included in the radio quality information calculation unit 12 of the first embodiment.

  In addition, activation base station selection section 101 includes service quality determination unit 1011, activation base station candidate selection unit 1012, and base station activation notification unit 1013.

  The activated base station selection unit 101 determines whether or not the required quality of service value for the UE 40 is satisfied based on the UE measurement information and the first load information reported from the activated base station 20, and To determine whether or not to activate the dormant base station 20. In the activation base station selection unit 101, the service quality determination unit 1011 determines whether or not the required service quality value for the UE 40 is satisfied.

  If the activated base station selection unit 101 determines that it is necessary to activate the inactive base station 20, the activated base station selection unit 101 selects a candidate for the inactive base station 20 to be activated as an activated base station candidate, and calculates radio quality information. Notification to the unit 102. This process is performed by the activation base station candidate selection unit 1012.

  The radio quality information calculation unit 102 estimates a change in radio quality of each UE 40 when the activated base station candidate is activated, and acquires second load information of each cell associated therewith. And the service quality calculation part 103 calculates the service quality estimated value of each UE40 at the time of starting a starting base station candidate.

  Then, the activated base station selection unit 101 selects a dormant base station 20 to be activated from the activated base station candidates based on the service quality estimation value. The activation base station selection unit 101 notifies the selected inactive base station 20 of an activation instruction. These processes are performed by the base station activation notification unit 1013 in the activation base station selection unit 101.

  The radio quality information calculation unit 102 estimates the RSRP of each UE 40 when the activation base station candidate is activated. In this estimation, the radio quality information calculation unit 102 refers to the UE measurement information reported from the base station 20 and the RSRP and location information database information held in the UE measurement information database 104. And the radio | wireless quality information calculation part 102 estimates the change of the connection cell of each UE40 after starting a starting base station candidate.

  That is, it is expected that the radio quality of each cell received by the UE 40 changes due to activation of the activation base station candidate, and handover caused by the change is performed. Therefore, the radio quality information calculation unit 102 estimates the RSRP of each UE 40 due to activation of the activation base station candidate, and predicts the change of the connected cell of each UE 40 based on the estimated RSRP. And the radio | wireless quality information calculation part 102 acquires the number of connected UEs which belong to each cell based on the change of the connected cell of each UE40. Here, the number of connected UEs of each cell acquired by the wireless quality information calculation unit 102 is treated as second load information which is new load information of each cell after starting the starting base station candidate.

  The service quality calculation unit 103 calculates an estimated value of the service quality of each UE 40 when the starting base station candidate is started. At this time, the service quality calculation unit 103 calculates the RSRP estimated value and the second load information calculated by the radio quality information calculation unit 102 and the first load information reported from the base station 20.

  Moreover, the service quality calculation part 103 can also calculate the estimated value of the service quality of each UE 40 as will be described later.

  Here, in this embodiment, the number of connected UEs in the base station 20, the actual service quality value of each UE 40, and the frequency block (Resource Block) usage rate are used as the first load information of the base station 20.

  A frequency block is a unit frequency block allocated for data transmission. The usage rate is the ratio of the number of frequency blocks actually allocated to the total number of frequency blocks that can be allocated within a predetermined time.

  The quality of service is the throughput of the UE 40. This is the time from the arrival of packet data to the base station buffer until the transmission of the packet data is completed, and the amount of transmission data per delay time is calculated. It is a thing.

  The UE measurement information database 104 is a database including a list in which location information is registered in association with RSRP of each cell measured at the location. The UE measurement information database 104 is created by collecting UE measurement information reported from each base station 20 as statistical data.

  FIG. 9 is a diagram illustrating an example of a registration list in the UE measurement information database 104.

  Referring to FIG. 9, position information indicated by latitude and longitude, and RSRP of each cell measured at the position are registered in order of strength (RSRP1, RSRP2, RSRP3, RSRP4).

  For example, at the position shown in the first row, the RSRP is received with an intensity of −80 dBm from the cell of cell ID1, −101 dBm from the cell of cell ID2, −117 dBm from the cell of cell ID3, and −119 dBm from the cell of cell ID4. . Also, at the position shown in the second row, RSRP is received at a strength of −85 dBm from the cell of cell ID2, −100 dBm from the cell of cell ID3, −111 dBm from the cell of cell ID5, and −112 dBm from the cell of cell ID1. The

  The configuration of the base station 20 of the second embodiment is the same as that of the base station 20 of the first embodiment described with reference to FIG.

  As an additional explanation, input / output information differs between the active base station 20 and the inactive base station 20. The active base station 20 reports (inputs) the UE measurement information from the UE 40 if the connected UE 40 exists, and reports the UE measurement information and the first load information of the base station 20 to the base station control device 100 ( Output. On the other hand, the inactive base station 20 is notified (input) of an activation instruction from the base station control device 100.

  The base station operation unit 201 is generally used in a mobile communication system, for example, in the communication from the base station 20 to the UE 40 (downward), by buffering the data of each UE 40 and transmitting the data to each UE 40. It has the same function as a base station.

  In the present embodiment, the base station operation unit 201 reports UE measurement information reported from the UE 40 to the base station control device 100. Further, the base station operation unit 201 measures the throughput as an actual measurement value of the service quality of each UE 40, and reports the first load information to the base station controller 100 together with the number of connected UEs and the frequency block usage rate at a predetermined cycle. .

  On the other hand, the activation control unit 202 performs activation and suspension control of the base station 20 based on the activation instruction received from the base station control apparatus 100 and the connected UE information.

  The operation of the present embodiment configured as described above will be described with reference to the flowcharts of FIGS.

  FIG. 10 is a flowchart illustrating the operation of the base station control device 100 according to the second embodiment. FIG. 11 is a flowchart showing a modification of the operation of the base station control device 100 of the second embodiment. FIG. 12 is a flowchart illustrating the operation of the base station 20 according to the second embodiment.

  First, FIG. 10 will be described.

  FIG. 10 is a flowchart illustrating a control operation in which the base station control device 100 selects a dormant base station 20 to be activated and notifies the activation instruction. The base station control apparatus 100 executes this operation at a predetermined cycle. In the present embodiment, this operation is executed at the reception timing of the UE measurement information and the first load information reported from the activated base station 20 in a predetermined cycle. In this embodiment, it is assumed that the number of idle base stations to be activated is one.

  As described above, the base station control device 100 receives UE measurement information and first load information from each active base station 20 in a predetermined cycle. Then, the measured throughput of each UE 40 is included in the first load information as an actual value of service quality.

  The activated base station selection unit 101 determines whether the current service quality of each UE 40, that is, the throughput satisfies the request (S201).

  In the present embodiment, when a target transmission rate is set for each application and there is a UE 40 whose measured value of throughput is smaller than the required value, it is determined that the service quality is not satisfied. Note that applications such as VoIP (Voice over Internet Protocol) and streaming are identified by QCI (QoS Classified Indicator), Service Class Indicator, and the like defined by 3GPP.

  In the present embodiment, it is determined that the service quality is not satisfied when at least one of the UEs 40 does not satisfy the requested value, but the ratio of the number of UEs 40 that satisfy the requested value is not limited to this. It is good also as a standard.

  For example, a predetermined satisfaction rate may be set, and it may be evaluated whether the ratio of the number of UEs 40 that satisfy the service quality requirement value has reached the satisfaction rate. When the predetermined satisfaction rate is 95%, it is determined that the service quality is satisfied when 95% or more of the UEs 40 satisfy the required value. Conversely, if the number of UEs 40 that satisfy the required value is less than 95%, it is determined that the service quality is not satisfied. Thereby, the case where the reception power from a cell is very weak, such as a room surrounded by a wall, and there is a possibility that an area where communication with the cell cannot be performed even if the base station 20 is activated may be considered.

  Further, the calculation of the satisfaction rate in this case may be performed for each cell, or may be performed for a specific area unit including a plurality of cells. For example, when it is performed for each cell, the operation of the flow of FIG. 10 is performed in units of cells.

  As described above, in step S201, the current service quality, that is, the throughput of each UE 40 is requested based on the measured value of the service quality included in the first load information received from each active base station 20. Whether or not the above is satisfied is determined. This process is executed by the service quality determination unit 1011 of the activated base station selection unit 101.

  However, the actual measured value of the throughput of the UE 40 with no transmission record in the latest throughput measurement period in the base station 20 is reported as zero.

  Therefore, the service quality determination unit 1011 causes the service quality calculation unit 103 to calculate an estimated value of the throughput of the UE 40 having no such transmission record, and based on the calculation result, whether or not the required service quality value is satisfied. You may make it determine.

  Hereinafter, calculation of the estimated value of the current throughput performed by the service quality calculation unit 103 will be described.

  First, an estimated value of SINR that is a ratio of received power (interference power) from other cells to thermal power with respect to received power (desired signal power) from a specific cell is calculated for each UE 40 using Equation (1). To calculate. SINR is an abbreviation for Signal-to-Interference-plus-Noise Ratio. Moreover, a specific cell means the connection cell of UE40 made into object.

SINR (i) = RSRP (i, j1) / {(RSRP (i, j2) * RU (j2) + RSRP (i, j3) * RU (j3) + ... + TN} Expression (1)
Here, i is an identification number (hereinafter referred to as ID) of the UE 40, j1 is an ID of a specific cell, j2, j3... Are IDs of other cells, RU (jx) is a frequency block usage rate of the cell ID jx, TN Represents thermal noise respectively.

  Since the interference power depends on the transmission frequency of neighboring cells, Equation (1) is an equation that takes into account the frequency block usage rate.

  Also, RSRP (i, j1) means RSRP received by UEi from the cell with cell ID j1, and RSRP (i, j2) and RSRP (i, j3) are cells with UEi being cell ID j2 and cell with cell ID j3. Means RSRP received respectively from

  As described above, the estimated value of SINR for each UE 40 is calculated based on the RSRP included in the UE measurement information and the frequency block usage rate included in the first load information.

  Next, using the estimated SINR calculated in Equation (1), a primary estimated value (UT_tmpest) of throughput for each UE 40 is calculated from Equation (2) using Shannon's communication capacity.

UT_tempest (i) = (BW / Nue (j1)) × log2 (1 + SINR (i)) [Mbps] Expression (2)
Here, BW represents the system bandwidth, and Nue (j) represents the number of connected UEs in the cell of the cell ID j1 to which UEi is connected. The number of connected UEs is included in the first load information.

  Finally, the UE throughput estimate (UT_est) is calculated from Equation (3).

UT_est (i) = UT_tempest (i) × Wut (j1) [Mbps] (3)
Here, Wut represents a throughput correction coefficient.

  Wut is a coefficient for correcting an error between the actually measured value and the estimated value of the throughput, and is calculated from Expression (4).

Wut (j1) = {UT_mes (k1) / UT_tmpest (k1) + UT_mes (k2) / UT_tmpest (k2) +... UT_mes (kx) / UT_tempest (kx)} / Nue '(j1) (4) )
Here, k1, k2,..., Kx are IDs of UEs 40 that are reported with a measured throughput value (UT_mes) larger than zero, and Nue ′ (j1) (<= Nue (j1)) in total. There are UEs 40.

  As described above, in the present embodiment, it is determined in step S101 whether or not the required value is satisfied based on the actually measured value of the throughput. However, the estimated value is calculated using Equation (3), and all the values are calculated. The UE 40 may also make a determination based on this estimated throughput value.

  If all the UEs 40 satisfy the service quality in step S201, the operation is terminated (S201, Yes).

  On the other hand, when there is a UE 40 that does not satisfy the service quality (S201, No), the activated base station selection unit 101 selects a candidate for the dormant base station 20 to be activated (S202). At this time, the activation base station candidate selection unit 1012 executes the process.

  In this case, the idle base station 20 that can manage the neighboring cells of the connected cell of the UE 40 that does not satisfy the service quality is a candidate. The neighboring cell may be a cell in which a difference in signal reception level is within a predetermined value with respect to a cell to which the UE 40 that does not satisfy the service quality is connected, or is installed in a geographical proximity. The cell of the base station 20 may be used. In the former case, the activation base station candidate selection unit 1012 may be configured to refer to the UE measurement information database 104.

  However, if all the neighboring base stations 20 are activated, the number of candidates for the idle base station 20 to be activated is zero, and no candidate can be selected.

  In step 203, the activation base station candidate selection unit 1012 determines whether or not an activation base station candidate that is a dormant base station candidate to be activated has been selected. If it can be selected, the process proceeds to step S204 (S203, Yes), and if it cannot be selected, the operation is terminated (S203, No).

  The operations from the next step S204 to step S208 are processes executed for each selected activated base station candidate. That is, when a plurality of activation base station candidates are selected, the operations from step S204 to step S208 are repeated for each activation base station candidate.

  Note that the processes of steps S205 and S206 are executed by the wireless quality information calculation unit 102, and the process of step S207 is executed by the service quality calculation unit 103.

  When the activation base station candidate can be selected in step S203, the activation base station candidate selection unit 1012 causes the radio quality information calculation unit 102 to change the radio quality of each UE 40 when the selected candidate is activated and A change in the connected cell of the UE 40 is predicted.

  That is, the radio quality information calculation unit 102 estimates the RSRP of each UE 40 in step S205, and predicts the connected cell of each UE 40 based on the estimated RSRP in step S206. And the radio | wireless quality information calculation part 102 acquires the number of connected UEs which belong to each cell after starting a starting base station candidate as 2nd load information.

  Based on the estimated value of RSRP of each UE 40 processed by the radio quality information calculation unit 102, the second load information, etc., the service quality calculation unit 103 obtains the estimated value of the throughput of each UE 40 after starting the activation base station candidate. calculate. Then, the calculation result of the service quality calculation unit 103 is reported to the activation base station selection unit 101.

  First, the RSRP estimation operation for each UE 40 when the radio quality information calculation unit 102 activates the dormant base station 20 that is the activation base station candidate, which is executed in step S205, will be described.

  The radio quality information calculation unit 102 estimates the RSRP for each UE 40 when the candidate candidate base station 20 is activated using the position information of the UE 40.

  For this estimation, an RF (Radio Frequency) pattern matching technique is used with reference to the UE measurement information database 104.

  That is, using the location information and radio quality information (RSRP) registered in the UE measurement information database 104 shown in FIG. 9, the RSRP at the latitude and longitude corresponding to the location closest to the reported location information of the UE 40 is extracted. To do.

  At this time, in the data of the UE measurement information database 104, the RSRP of the cell ID corresponding to the dormant base station is treated as 0, but the RSRP of the cell ID corresponding to the activated dormant base station is the content of the database. It shall be received with strength. For example, when the position of the UE 40 is in the vicinity of the latitude and longitude shown in the second line of the UE measurement information database 104 shown in FIG. 9, the cell ID 2 is inactive, and this cell ID 2 is activated as an activation base station candidate. Assuming that

  At the time when the cell ID 2 is dormant, the RSRP that the UE 40 can receive most strongly is −100 dBm from the cell ID 3. However, assuming that this dormant cell ID 2 is activated, the UE 40 can receive RSRP from the cell ID 2 with an intensity of −85 dBm.

  Here, the position closest to the position information of the UE 40 is a position where the sum of squares of the difference between the latitude and longitude of the position information reported from the UE 40 and the latitude and longitude registered in the database is minimized. As another method, a plurality of RSRPs in the latitude / longitude of the database in which the latitude and longitude of the position information reported from the UE 40 are close may be selected as the grid points, and the RSRP may be calculated by interpolation.

  Next, the radio quality information calculation unit 102 predicts the connected cell of each UE 40 using the estimated value of RSRP in each UE 40 when the activation target activation base station candidate calculated in step S205 is activated. (S206).

That is, the presence / absence of handover is predicted based on the RSRP change in each UE 40 due to activation of the dormant base station 20. Specifically, assuming that UEi is connected to cell J1, using the RSRP strength difference between adjacent cells and its offset value, if equation (5) is established as follows, UEi is handed over: Assuming that
RSRP (i, J1) -RSRP (i, J2) <Offset1 (J1) -Offset2 (J1, J2) (5)
Here, RSRP (i, J1) and RSRP (i, J2) indicate RSRP for UEi cell J1 and RSRP for cell J2, Offset1 is an offset set only in cell J1, and Offset2 is in cell J1 and cell J2. Indicates the common offset to set.

  As described above, when the dormant base station 20 that is a starting base station candidate is activated, the radio quality received by the UE 40 changes, and accordingly, when the connected cell of the UE 40 changes, the connected UE belonging to each cell The number changes. The radio quality information calculation unit 102 acquires, as the second load information, the number of connected UEs belonging to each cell after starting the startup base station candidate based on the change in the connected cell of the UE 40.

  When the estimated value of RSRP of each UE 40 and the second load information of each cell are obtained, the service quality calculation unit 103 estimates the throughput (UT_est) of each UE 40 due to activation of the target activated base station candidate. (I) ′) is calculated (S207).

  The service quality calculation unit 103 calculates the estimated value of the throughput of each UE 40 using the equations (1) to (3) described above.

  Note that the throughput calculation according to the above-described equations (1) to (3) is an estimated value of the throughput of the UE 40 at the present time, whereas the throughput calculated here is the throughput of the UE 40 due to activation of the activation base station candidate. Is an estimated value. For this reason, there are two differences in the values of the parameters to be used, compared with the explanations of the above-described equations (1) to (3).

  The first point is that the RSRP in the UE 40 changes due to activation of the dormant base station 20 that is the activation base station candidate.

  The 2nd point is that the connection cell of UE40 changes with the change of RSRP in UE40, and the number of connected UEs in each base station 20 changes. This change in the number of connected UEs also leads to a change in the frequency block usage rate.

  Therefore, in the calculation of SINR in the equation (1) after starting the starting base station candidate, RSRP uses the RSRP predicted by the radio quality information calculation unit 102 in step S205, and the frequency block usage rate (RU ′) is as follows: Equations (6) and (7) are used.

RU ′ (j) = {RU (j) / Nue (j)} × Nue ′ (j) (Nue> 0) (6)
RU ′ (j) = {RU (l) / Nue (l)} × Nue ′ (j) (Nue = 0) (7)
The above equation (6) is applied to the base station where the currently connected UE exists, and the equation (7) is used for the base station where the currently connected UE does not exist. Therefore, the formula (7) is used for the activated base station 20 that is in a suspended state.

  Note that “l” represents a cell other than the cell ID j, and an arbitrary cell ID in which the connected UE exists is used.

  In addition, for a base station to which no currently connected UE exists, instead of Equation (7), for example, an average value of RU and Nue of neighboring base stations of the activated base station 20 (add _ave to the parameter name) (8) using) may be used.

RU ′ (j) = {RU_ave / Nue_ave} × Nue ′ (j) (N_ue = 0) (8)
In the above, RU (j) and Nue (j) indicate the frequency block usage rate and the number of connected UEs in the cell of cell IDj, respectively, included in the first load information. Nue ′ (j) indicates the number of connected UEs in the cell of the cell IDj after the activation base station candidate that is the second load information is activated.

  Further, Nue (j) in the calculation of the primary estimated value (UT_tmpest) of the throughput of the UE 40 in Expression (2) is also the number of connected UEs (Nue ′ (j)) in the cell of the cell IDj after starting the starting base station candidate Is used.

  As described above, the number of connected UEs (Nue ′ (j)) in the cell of the cell IDj after starting the starting base station candidate as the second load information is obtained by the connected cell prediction of each UE 40 in step S206. .

  When the calculation of the throughput estimation value of each UE 40 when the activated base station candidates selected in step S202 are activated is completed for all the selected candidates (loop of S204 to S208), the activated base station selection unit 101 Select a base station to be activated.

  Here, the activation base station selection unit 101 compares the minimum throughput estimation value when each of the selected activation base station candidates is activated, and the activation base station candidate having the maximum minimum value is in an idle state. The base station 20 is selected (S209).

  Then, the activation base station selection unit 101 notifies an activation instruction to the selected base station (S210). Note that the processing of steps S209 and S210 is executed by the base station activation notification unit 1013.

  The operation of the base station control device 100 of this embodiment has been described above with reference to FIG.

  In this embodiment, the throughput is used as the service quality, but the delay time may be used as the service quality. Applications such as VoIP and moving images are required to complete transmission at regular intervals. Alternatively, the throughput and the delay time may be normalized, and the sum or product calculated may be newly defined as the service quality index.

  Further, in the present embodiment, the operation of FIG. 10 is executed at the reception timing of the UE measurement information and the first load information reported from the base station 20 at a predetermined cycle. However, it may be executed immediately when the load on the base station 20 changes due to connection of a new UE or a handover UE.

  Furthermore, in this embodiment, the RSRP when the dormant base station is activated is estimated using the position information indicated by the UE measurement information database 104 and the RSRP of each cell corresponding to the position. Alternatively, RSRP may be estimated by a three-point surveying method using a database of only four or more RSRPs including a dormant base station.

  In addition, you may use the operation | movement which deform | transformed the operation | movement of this embodiment as follows, and the operation | movement of a modification as shown in FIG.

  In the operation described in FIG. 10, after the calculation for all candidates is completed by the loop processing of steps S204 to S208, the base station having the maximum minimum estimated throughput value is selected in step S209. . However, in order to shorten the processing time, if a starting base station candidate whose throughput estimation value satisfies the required criteria is found, the candidate base station may be immediately selected as the starting base station.

  That is, when the processing of steps S205 to S207 is performed, it is determined whether or not the throughput estimation value when the candidate is activated for each candidate can satisfy the request criterion. Station 20 may be selected as the starting base station.

  The operation described in FIG. 10 is carried out periodically once to maintain and improve the satisfaction of service quality. However, as shown in FIG. 11, after step 210, the operation may be performed so as to return to step 201 again.

  In other words, after the activation instruction is notified to the selected activation base station, the operation returns to step 201 again, and the operation may be repeated until the throughput satisfies the request or until the candidate of the activation base station cannot be selected. Good.

  Next, the operation of the base station 20 of this embodiment will be described with reference to FIG.

  FIG. 12 is a flowchart showing the start and stop operations of the base station by the start control means 202 of the base station 20. This operation is executed at a predetermined cycle.

  The activation control unit 202 determines whether or not the base station is currently suspended (S301).

  If it is suspended (S301, Yes), it is determined whether or not a notification of activation instruction has been received from the base station controller 100 (S302).

  When the activation instruction notification is received from the base station controller 100 (S302, Yes), the activation controller 202 activates the base station (S303). For example, when the power amplifier (Power Amplifier) is suspended, the power amplifier is activated. Alternatively, when the voltage of a specific circuit is dropped, the voltage is set so as to ensure the voltage during normal operation.

  On the other hand, when the notification of the activation instruction is not received from the base station control apparatus 100 (S302, No), the operation is terminated.

  If it is determined in step S301 that the base station is not idle (S301, No), the activation control unit 202 determines whether there is a connected UE 40 (S304).

  When there is no UE 40 connected to the base station (S304, Yes), the activation control unit 202 puts the base station into a dormant state (S305). If there is a connected UE 40 (S304, No), the operation is terminated.

  In this embodiment, the type of base station to be activated or deactivated is not limited. Small cell base stations with low transmission power and narrow communication areas are often installed for capacity measures, and macro cell base stations with large transmission power and wide communication areas should be installed to secure communication areas (coverage measures). There are many. Therefore, the base station to be activated or deactivated may be limited to the small cell base station.

  The second embodiment has been described above.

  As described above, in the present embodiment, when there is a UE 40 that does not satisfy the service quality, the service quality estimation value in each UE 40 when the dormant base station 20 is activated is calculated, and It is possible to determine which of the base stations 20 should be activated. Therefore, an optimal dormant base station can be activated in consideration of the user experience based on service quality, and an unnecessary increase in power consumption can be prevented.

  Further, according to the present embodiment, when selecting a base station to be activated from the selected activated base station candidates, the minimum values of the throughput estimation values when the respective stations are activated are compared, and the minimum value is maximized. Select the base station as the starting base station. Therefore, the optimal dormant base station 20 that can further improve the user experience can be activated.

  Next, a third embodiment will be described.

  In the second embodiment, one base station 20 that is inactive is activated. However, in this embodiment, a plurality of base stations 20 that are inactive can be activated. In the present embodiment, it is assumed that the maximum number of base stations 20 that can be activated by simultaneously notifying activation instructions is three.

  The configurations of the mobile communication system, the base station control device, and the base station of the third embodiment are the mobile communication system 2 and the base station control device 100 of the second embodiment described with reference to FIGS. And the same as the base station 20. Therefore, description of those configurations of the third embodiment is omitted. In addition, since the start and stop operations of the base station by the start control unit 202 of the base station 20 of the third embodiment are the same as those of the second embodiment, description of the operation of the base station 20 is also omitted. Furthermore, reference numerals used in the description of the third embodiment are the same as those in the second embodiment.

  The operation of the base station control device 100 of the third embodiment will be described.

  FIG. 13 is a flowchart illustrating the operation of the base station control device 100 according to the third embodiment.

  In FIG. 13, the following two points are different from the operation of the base station control apparatus 100 of the second embodiment described with reference to FIG.

  First, step S202 in FIG. 10 is changed to step S221 in FIG. And step S222 and step S223 were newly added between step S208 and step S209 of FIG.

  By executing the processing of the flow of FIG. 13, the base station control apparatus 100 executes a control operation for selecting a plurality of base stations 20 to be activated. Then, similarly to the second embodiment, the base station control device 100 executes this operation at a predetermined cycle. In the present embodiment, this operation is performed at the reception timing of the UE measurement information and the first load information reported in a predetermined cycle from the base station 20, but as described in the second embodiment as well. It is not limited to that.

  The activated base station selection unit 101 refers to UE measurement information and first load information received from each base station 20 in a predetermined cycle, and requests the current service quality of each UE 40, that is, throughput for each application. Whether or not the above is satisfied is determined. This operation is the same as the operation in step S201 described with reference to FIG. This process is executed by the service quality determination unit 1011 of the activated base station selection unit 101.

  If it is determined in step S201 that there is a UE 40 that does not satisfy the service quality (No in S201), the activated base station selection unit 101 determines that the activated base station combination is a candidate combination of the dormant base stations 20 to be activated. A candidate is selected (S221). At this time, the activation base station candidate selection unit 1012 executes the process.

  In this case, a plurality of dormant base stations 20 that can manage the neighboring cells of the connected cell of the UE 40 that does not satisfy the service quality are targeted for combination. The neighboring cell may be a cell in which a difference in signal reception level is within a predetermined value with respect to a cell to which the UE 40 that does not satisfy the service quality is connected, or is installed in a geographical proximity. The cell of the base station 20 may be used. In the former case, the activation base station candidate selection unit 1012 may be configured to refer to the UE measurement information database 104.

  For example, when there are four base stations 20 of N11, N12, N13, and N14 as neighboring cells, the following 4 + 6 + 4 = 14 candidates are selected as activation base station combination candidates.

  In the case of a combination of only one station, there are four candidates (N11), (N12), (N13), and (N14). When two stations are combined, there are six candidates (N11, N12), (N11, N13), (N11, N14), (N12, N13), (N12, N14), (N13, N14). . In the case of a combination of three stations, there are four candidates (N11, N12, N13), (N11, N12, N14), (N11, N13, N14), and (N12, N13, N14).

  However, if all the base stations 20 are activated, the number of candidate activated base station combinations is zero, and no candidate can be selected, and the activated base station candidate selection unit 1012 ends the operation in step 203. (S203, No).

  On the other hand, when the activation base station combination candidate as described above can be selected (S203, Yes), the process proceeds to step S204, and the operations from step S204 to S208 are repeated for each of the activation base station combination candidates.

  As described with reference to FIG. 10, the processes of steps S205 and S206 are executed by the wireless quality information calculation unit 102, and the process of step S207 is executed by the service quality calculation unit 103.

  Further, the processing in steps S205 to S207 is as described in the second embodiment with reference to FIG. The difference is that the activated base station combination candidate may include a plurality of dormant base station candidates to be activated.

  When the activation base station combination candidate can be selected, the activation base station candidate selection unit 1012 causes the radio quality information calculation unit 102 to change the radio quality for each UE 40 when the base station 20 included in the combination is activated, The change of the connected cell of each UE 40 based on this is predicted.

  That is, the radio quality information calculation unit 102 estimates the RSRP of each UE 40 in step S205, and predicts the connected cell of each UE 40 based on the estimated RSRP in step S206. Then, the radio quality information calculation unit 102 acquires the number of connected UEs belonging to each cell after starting the base station 20 included in the starting base station combination candidate as second load information.

  Based on the estimated value of RSRP of each UE 40 processed by the radio quality information calculation unit 102, the second load information, etc., the estimated value of the throughput of each UE 40 after starting the base station 20 included in the starting base station combination candidate Is calculated by the service quality calculation unit 103. Then, the calculation result of the service quality calculation unit 103 is reported to the activation base station selection unit 101.

  When the above processing (loop of S204 to S208) is completed for all candidates for the starting base station combination candidate selected in step S221, the starting base station combination candidate to be actually started is selected. This processing is executed by the base station activation notification unit 1013 of the activation base station selection unit 101.

  First, in step S222, the base station activation notification unit 1013 determines whether or not there is an activation base station combination candidate whose throughput estimation value satisfies the request by activating the base station 20 included in the combination. .

  When there is such a start base station combination candidate (S222, Yes), the base station start notification unit 1013 narrows down to start base station combination candidates with the smallest number of base stations included in the combination (S223).

  For example, three startup base station combination candidates (N11, N12), (N12, N14), (N11, N13, N14) request throughput estimates by starting the base stations 20 included in each combination. Assume that it is determined that the candidate satisfies the above.

  In this case, it is narrowed down to two starting base station combination candidates (N11, N12) and (N12, N14) with a small number of starting base stations. In other words, the starting base station combination candidates that require less power consumption are narrowed down.

  Then, the base station activation notifying unit 1013 compares the minimum estimated throughput values when the activated base station 20 included in each combination is compared with the narrowed activated base station combination candidates, and the minimum value is the maximum. Is selected (S209).

  Then, the base station activation notification unit 1013 notifies the activation instruction to the base station 20 included in the selected activation base station combination candidate (S210). That is, when the selected starting base station combination candidate is composed of a plurality of dormant base stations 20, the plurality of dormant base stations 20 are activated simultaneously.

  If it is determined in step S222 that there is no candidate whose throughput estimation value satisfies the request even if the base station 20 included in the combination is activated (S222, No), the base station activation notification unit 1013 Shifts the processing to step S209. In other words, service quality cannot be satisfied, but offloading is performed by starting the base station included in the starting base station combination candidate that maximizes the minimum throughput estimation value, and throughput is improved even a little. It is expected that

  The third embodiment has been described above.

  As described above, in the present embodiment, when there is a UE 40 that does not satisfy the service quality, the service quality estimation value in each UE 40 when the dormant base station 20 is activated is calculated, and It is possible to determine which of the base stations 20 should be activated. Therefore, an optimal dormant base station can be activated in consideration of the user experience based on service quality, and an unnecessary increase in power consumption can be prevented.

  Further, according to the present embodiment, when selecting an activation base station combination candidate, a combination candidate that minimizes the number of activated base stations is selected. Therefore, even if the base station is activated, the power consumption can be reduced.

  Furthermore, according to the present embodiment, when selecting a starting base station combination candidate, the minimum value of the throughput estimation value when the base station included in each combination is started is compared, and the minimum value becomes the maximum. Select a candidate. For this reason, it is possible to activate the dormant base station 20 in an optimal combination that can further improve the user experience.

  Next, a fourth embodiment will be described.

  In each of the above-described embodiments, the base station controller determines whether or not there is a UE that does not satisfy the service quality, and when there is a UE that does not satisfy the service quality, an optimal dormant base considering the user experience Configured to start the station. However, the base station may be configured to execute these controls instead of the base station controller.

  FIG. 14 is a block diagram showing the configuration of the mobile communication system according to the fourth embodiment.

  Referring to FIG. 14, the mobile communication system 3 according to the present embodiment includes a main base station 21, sub-base stations 22-1 to 22-3, and user terminals (UE) 40-1 and 40-2. .

  The main base station 21 is a macro base station, and the cell 31 is formed, and the sub base stations 22-1 to 22-3 are arranged as small base stations in spots in areas where traffic demand is high. That is, the cells 32-1 to 32-3 formed by the sub base stations 22-1 to 22-3 are included in the cell 31.

  Here, it is assumed that the secondary base station 22-1 indicated by a solid line is being activated, and the secondary base stations 22-2 and 22-3 indicated by dotted lines are being suspended.

  The main base station 21 and the activated sub base station 22-1 manage the cell 31 and the cell 32-1, respectively, and perform bidirectional communication with the UEs 40-1 and 40-2 using the own cell as a connection cell. I do. Further, the main base station 21 and the activated sub base station 22-1 acquire UE measurement information from the UEs 40-1 and 40-2 and measure the load of the own cell.

  The main base station 21 and the activated sub base station 22-1 are connected to an upper network such as a core network, and relay traffic between the UEs 40-1 and 40-2 and the upper network.

  The main base station 21 and the sub base stations 22-1 to 22-3 are each connected by a communication line, and are configured to be able to transmit information to each other (for example, LTE X2 interface). Then, the main base station 21 has a configuration that the base station control device of each of the above-described embodiments includes that is configured to activate an optimal dormant base station in consideration of the user experience.

  That is, the main base station 21 manages the first load information of the main base station 21 including the actually measured value of the service quality of the UE 40-1 using the cell 31 as the connection cell, and the UE measurement information reported by the UE 40-1. . Also, the main base station 21 acquires the first load information and UE measurement information of the sub base station 22-1 from the active sub base station 22-1. Then, the main base station 21 performs activation control of the suspended sub base stations 22-2 and 22-3 based on these management information and acquisition information.

  FIG. 15 is a block diagram illustrating a configuration of the main base station 21 according to the fourth embodiment.

  The configuration of the main base station 21 of the fourth embodiment is the same as the configuration of the base station control device 100 described with reference to FIG. The main base station 21 also includes base station operation means 201 included in the base station 20 described with reference to FIG.

  That is, the main base station 21 of the fourth embodiment is configured to include an activation base station selection unit 211, a radio quality information calculation unit 212, a service quality calculation unit 213, and a UE measurement information database 214. In addition, activation base station selection section 211 includes service quality determination unit 2111, activation base station candidate selection unit 2112, and base station activation notification unit 2113.

  Note that the base station operation means 201 (not shown) includes the first load information of the main base station 21 including the actual measurement value of the service quality of the UE 40 using the cell 31 managed by the main base station 21 as the connection cell, and the UE 40 Collect UE measurement information to report. Here, the first load information and the UE measurement information are the same as those described in the second embodiment.

  Since the functions of each configuration are almost the same as the functions described in the second embodiment, only the outline will be described below.

  The service quality determination unit 2111 of the activated base station selection unit 211 manages the first load information of the main base station 21 and UE measurement information reported from the UE 40 having the cell 31 as a connected cell. Further, the service quality determination unit 2111 receives the first load information of the active sub base station 22 and the UE measurement information reported to the sub base station 22 by the UE 40 having the sub base station 22 as a connected cell. The presence / absence of the UE 40 that does not satisfy the predetermined service quality is determined. The first load information includes an actual value of service quality of each UE 40, and the UE measurement information includes the reported location information of the UE 40 and the radio quality information of each cell measured at the location. .

  When there is a UE 40 that does not satisfy the service quality, the activation base station candidate selection unit 2112 of the activation base station selection unit 211 can manage the neighboring base station of the connected cell of the UE 40 that does not satisfy the service quality. Station 22 is selected as a starting base station candidate.

  The radio quality information calculation unit 212 estimates the radio quality information of each cell measured by each UE 40 as the estimated radio quality information when the activated base station candidate is activated, and based on the estimated radio quality information, the activated base station The connected cell of each UE 40 after starting the candidate is predicted. And the radio | wireless quality information calculation part 212 acquires the number of connected UEs which belong to each cell after starting a starting base station candidate as 2nd load information.

  Based on the estimated radio quality information, the first load information, and the second load information, the service quality calculation unit 213 uses the estimated service quality value of each UE 40 after activating the activated base station candidate as the service quality estimated value. calculate.

  The base station activation notification unit 2113 of the activation base station selection unit 211 selects one of the activation base station candidates as an activation base station based on the service quality estimation value, and the selected sub base station 22 is suspended. Notify the start instruction to shift to the start state.

  The estimation of the estimated radio quality information and the prediction of the predicted connected cell by referring to the UE measurement information database 214 by the radio quality information calculation unit 212 are the same as those described in the second embodiment.

  The calculation of the service quality estimated value by the service quality calculation unit 213 is the same as the content described in the second embodiment. Similarly to the second embodiment, the service quality determination unit 2111 determines the UE 40 that does not satisfy the predetermined service quality based on the current service quality estimation value of each UE 40 calculated by the service quality calculation unit 213. The presence or absence may be determined.

  The above is the configuration of the main base station 21 of the fourth embodiment.

  Then, the main base station 21 performs the same operation as that described with reference to FIGS. That is, the main base station 21 determines whether or not there is a UE 40 that does not satisfy the service quality. If there is a UE 40 that does not satisfy the service quality, the optimum base station is activated in consideration of the user experience. Control.

  The configuration of the sub base station 22 of the fourth embodiment is the same as the configuration of the base station 20 of the first embodiment described with reference to FIG.

  That is, the sub base station 22 includes a base station operation unit 201 and a start control unit 202.

  The base station operation means 201 includes first load information of the sub base station 22 including actual measured values of service quality of the UE 40 using the cell 32 managed by the sub base station 22 as a connected cell, and UE measurement reported by the UE 40. Information is reported to the main base station 21.

  When the activation control unit 202 receives the activation instruction notification from the main base station 21, the activation control unit 202 activates a predetermined apparatus operation that is suspended.

  The sub base station 22 performs the operation described with reference to FIG.

  The fourth embodiment has been described above.

  As described above, the present embodiment also calculates a service quality estimate value in each UE 40 when the sub base station 22 that is inactive is activated when there is a UE 40 that does not satisfy the service quality. It can be determined which of the sub-base stations 22 to activate. Therefore, an optimal dormant base station can be activated in consideration of the user experience based on service quality, and an unnecessary increase in power consumption can be prevented.

  Furthermore, also in the present embodiment, the sub base station 22 can be activated with less power consumption, and the optimal combination of the idle sub base stations 22 that can improve the user experience can be activated. it can.

  Note that the hardware configurations of the base station control device 100 and the main base station 21 described after the second embodiment have the same configuration as the block diagram described with reference to FIG.

  The base station control device 100 and the main base station 21 operate from hardware components such as LSI (Large Scale Integration) in which a program for realizing each function is incorporated in the base station control device 100 or the main base station 21. It may be realized by mounting circuit components.

  Further, the base station control device 100 and the main base station 21 may be realized in software by executing a program that provides each function of each component by a CPU on a computer processing device. The program of each embodiment is a program for causing a computer to function as each functional unit in each of the above-described embodiments. For example, a functional unit having the same configuration as the functional unit described with reference to FIG. 6 is realized. To do.

  Moreover, the embodiment may be such that those programs are supplied from the system or remotely, and the base station control device 100 and the main base station 21 execute the processing of the operation procedure described in each embodiment.

  And the medium which stored those programs, and the server which downloads the programs are also contained under the category of the present invention.

In addition, although a part or all of said embodiment can be described also as the following additional remarks, it is not restricted to the following.
(Additional remark 1) The 1st load of this base station including the measured value of the service quality of the user terminal which uses the cell which this base station manages from each of the some base station arranged in the predetermined area as a connection cell Information and UE (User Equipment) measurement information including location information and radio quality information of each cell measured at the location, reported to the base station by the user terminal, and satisfying a predetermined service quality When there is no user terminal, the activated base station selection means for selecting a dormant base station that can manage a neighboring cell of the connected cell of the user terminal that does not satisfy the service quality as an activated base station candidate;
When the activated base station candidate is activated, radio quality information of each cell measured by the user terminal is estimated as estimated radio quality information, and a change in the connected cell of the user terminal is predicted based on the estimated radio quality information Radio quality information calculation means for acquiring second load information of each of the activated base stations after activating the activated base station candidate;
Based on the estimated radio quality information, the first load information, and the second load information, a service quality estimate value of the user terminal after starting the activation base station candidate is calculated as a service quality estimate value. Service quality calculation means;
With
The activated base station selecting means selects one of the activated base station candidates as a base station to be activated based on the service quality estimation value, and causes the selected base station to shift from an inactive state to an activated state A base station control device that notifies an activation instruction.
(Additional remark 2) The said starting base station selection means compares the said service quality estimated value at the time of starting each said starting base station candidate, The said starting base station candidate from which the minimum value of the said service quality estimated value becomes the maximum The base station control device according to appendix 1, wherein the base station control device is selected as a base station to be activated.
(Additional remark 3) The said starting base station selection means selects all the combinations of several dormant base stations which can manage the periphery cell of the connection cell of the said user terminal which is not satisfied with the said quality of service, starting base station combination candidate Select as
The radio quality information calculation means estimates the estimated radio quality information when a base station included in the activated base station combination candidate is activated, and changes a connection cell of the user terminal based on the estimated radio quality information. Predicting and obtaining the second load information of each of the activated base stations after activating the base stations included in the activated base station combination candidates,
The service quality calculation means, based on the estimated radio quality information, the first load information, and the second load information, the service quality estimation after starting a base station included in the start base station combination candidate Calculate the value
The activation base station selection unit compares the service quality estimation values when the activation base station combination candidates are activated, satisfies the service quality estimation value and minimizes the number of base stations to be activated. The base station control apparatus according to appendix 1, wherein a station combination candidate is selected, and the start instruction is notified to all base stations included in the selected start base station combination candidate.
(Additional remark 4) The said radio | wireless quality information calculation means refers to the said UE measurement information, the location information, and the database previously registered corresponding to the radio | wireless quality information of each cell measured by this position, Any one of appendix 1 to appendix 3, wherein estimated radio quality information is estimated, and whether or not a handover of the user terminal is determined based on the estimated radio quality information to predict a change in a connected cell of the user terminal The base station control device described in the supplementary note.
(Supplementary note 5) The base station control device according to any one of supplementary notes 1 to 4, wherein the service quality is a throughput or a transmission delay time of the user terminal measured by the base station.
(Supplementary Note 6) The first load information includes the throughput of the user terminal connected to the connected cell, the number of user terminals connected to the connected cell, and the frequency block (Resource Block) usage rate measured by the base station. Including
The service quality calculation unit calculates a current throughput estimate of the user terminal using the UE measurement information and the first load information as parameters, and the activation base station selection unit calculates the calculation by the service quality calculation unit. The base station control device according to any one of supplementary notes 1 to 4, wherein the presence / absence of the user terminal that does not satisfy a predetermined service quality is determined using a result.
(Supplementary note 7) The second load information is the number of user terminals connected to each of the activated base stations in accordance with a change in the connected cell of the user terminal after activating the activated base station candidate,
The service quality calculation means uses the estimated radio quality information, the number of user terminals connected to the connected cell included in the first load information, the second load information, and the frequency block usage rate as parameters. The base station control device according to appendix 6, wherein the service quality estimation value of the user terminal after starting a base station candidate is calculated.
(Additional remark 8) The said starting base station selection means is the presence or absence of the said user terminal which does not satisfy predetermined | prescribed service quality triggered by having changed the load of the said connection cell by the predetermined period or the change of the number of user terminals. The base station control device according to any one of supplementary notes 1 to 7, characterized by:
(Supplementary note 9) A plurality of base stations deployed in a predetermined area, and a base station controller for controlling the plurality of base stations,
The base station control device is the base station control device according to any one of supplementary notes 1 to 8,
Each of the plurality of base stations is
The first load information of the base station including the measured value of the service quality of the user terminal having the cell managed by the base station as the connection cell, the position information reported by the user terminal, and each measured at the position Base station operation means for reporting UE (User Equipment) measurement information including radio quality information of the cell to the base station control device;
A mobile communication system, comprising: a start control unit that starts a predetermined apparatus operation during suspension when receiving the start instruction notification from the base station control apparatus.
(Supplementary Note 10) A first base station and a plurality of second base stations arranged in a predetermined area,
The first base station is
The load information of the first base station including the measured value of the service quality of the user terminal having the cell managed by the first base station as the connection cell and the cell managed by the second base station as the connection cell The first load information, which is the load information of the second base station including the measured value of the service quality of the user terminal, the position information of the user terminal reported to the first base station, and the measured position. UE (User Equipment) measurement information including radio quality information of each cell and the UE measurement information reported to the second base station, and whether there is a user terminal that does not satisfy a predetermined service quality Service quality determination means for determining;
When the service quality determination means determines that there is the user terminal that does not satisfy the service quality, the second idle terminal that can manage the neighboring cells of the connected cell of the user terminal that does not satisfy the service quality A starting base station candidate selecting means for selecting the base station as a starting base station candidate;
When the activated base station candidate is activated, radio quality information of each cell measured by the user terminal is estimated as estimated radio quality information, and a change in the connected cell of the user terminal is predicted based on the estimated radio quality information Radio quality information calculation means for acquiring second load information of each of the activated base stations after activating the activated base station candidate;
Based on the estimated radio quality information, the first load information, and the second load information, a service quality estimate value of the user terminal after starting the activation base station candidate is calculated as a service quality estimate value. Service quality calculation means;
Based on the service quality estimation value, select one of the activated base station candidates as a base station to be activated, and notify the selected second base station of an activation instruction for shifting from an inactive state to an activated state Each of the plurality of second base stations includes:
The first load information of the second base station including the measured value of the service quality of the user terminal having the cell managed by the second base station as a connected cell and the UE measurement information reported by the user terminal Base station operating means for reporting to the first base station;
A mobile communication system, comprising: an activation control unit that activates a predetermined apparatus operation during suspension when receiving the activation instruction notification from the first base station.
(Additional remark 11) The said base station starting notification means compares the said service quality estimated value at the time of each starting the said starting base station candidate, The said starting base station candidate from which the minimum value of the said service quality estimated value becomes the maximum The mobile communication system according to appendix 10, wherein the mobile communication system is selected as a second base station to be activated.
(Additional remark 12) The said starting base station candidate selection means, all the combinations of a plurality of said 2nd base stations in suspension which can manage the periphery cell of the connection cell of the said user terminal which is not satisfied with the said service quality, Select as starting base station combination candidate,
The radio quality information calculation means estimates the estimated radio quality information when the second base station included in the activated base station combination candidate is activated, and the connected cell of the user terminal based on the estimated radio quality information The second load information of each of the first base station and the activated second base station after the activation of the second base station included in the activated base station combination candidate is predicted. Acquired,
The service quality calculation unit is configured to start the second base station included in the start base station combination candidate based on the estimated radio quality information, the first load information, and the second load information. Calculate service quality estimates,
The base station activation notifying means compares the service quality estimated values when the activated base station combination candidates are activated, satisfies the service quality estimated value, and determines that the number of second base stations to be activated is minimum. 11. The mobile communication system according to appendix 10, wherein the activation base station combination candidate is selected, and the activation instruction is notified to all second base stations included in the selected activation base station combination candidate.
(Additional remark 13) The said radio | wireless quality information calculation means refers to the said UE measurement information, the location information, and the database previously registered corresponding to the radio | wireless quality information of each cell measured by this position, Any one of Supplementary Note 10 to Supplementary Note 12, wherein estimated wireless quality information is estimated, and a change in the connected cell of the user terminal is predicted by determining whether or not the user terminal is handed over based on the estimated wireless quality information The mobile communication system according to the supplementary note.
(Supplementary note 14) The mobile communication system according to any one of supplementary notes 10 to 13, wherein the service quality is a throughput or a transmission delay time of the user terminal.
(Supplementary Note 15) The first load information includes a throughput of the user terminal connected to the connected cell, a number of user terminals connected to the connected cell, and a frequency block (Resource Block) usage rate.
The service quality calculation means calculates a current throughput estimation value of the user terminal using the UE measurement information and the first load information as parameters, and the service quality judgment means calculates the calculation result by the service quality calculation means. The mobile communication system according to any one of Supplementary Note 10 to Supplementary Note 13, wherein the presence / absence of the user terminal that does not satisfy a predetermined service quality is determined using a mobile phone.
(Supplementary Note 16) The second load information is the number of user terminals connected to each of the activated base stations accompanying a change in the connected cell of the user terminal after activating the activated base station candidate,
The service quality calculation means uses the estimated radio quality information, the number of user terminals connected to the connected cell included in the first load information, the second load information, and the frequency block usage rate as parameters. The mobile communication system according to supplementary note 15, wherein the service quality estimation value of the user terminal after starting a base station candidate is calculated.
(Additional remark 17) The said service quality determination means determines the presence or absence of the said user terminal which is not satisfying predetermined service quality triggered by the load of the said connection cell having changed by the predetermined period or the change of the number of user terminals. The mobile communication system according to any one of supplementary notes 10 to 16, characterized by:
(Additional remark 18) The 1st load of this base station including the measured value of the service quality of the user terminal which uses the cell which this base station manages from each of several base stations arranged in the predetermined area as a connection cell Information and UE (User Equipment) measurement information including location information and radio quality information of each cell measured at the location, reported to the base station by the user terminal, and satisfying a predetermined service quality The presence or absence of the user terminal that is not,
When it is determined that there is the user terminal that does not satisfy the service quality, a dormant base station that can manage a neighboring cell of a connection cell of the user terminal that does not satisfy the service quality is set as a starting base station candidate. Selected,
When the activated base station candidate is activated, radio quality information of each cell measured by the user terminal is estimated as estimated radio quality information, and a change in the connected cell of the user terminal is predicted based on the estimated radio quality information And obtaining the second load information of each of the activated base stations after activating the activated base station candidate,
Based on the estimated radio quality information, the first load information, and the second load information, a service quality estimate value of the user terminal after starting the startup base station candidate is calculated as a service quality estimate value. ,
Based on the service quality estimation value, selecting any one of the activated base station candidates as a base station to be activated, and notifying the selected base station of an activation instruction for shifting from an inactive state to an activated state A base station control method.
(Supplementary note 19) When selecting any one of the starting base station candidates as a base station to be started,
Comparing the service quality estimation values when the activation base station candidates are respectively activated, and selecting the activation base station candidate having the smallest minimum service quality estimation value as a base station to be activated, The base station control method according to appendix 18.
(Supplementary Note 20) When it is determined that there is the user terminal that does not satisfy the service quality,
Select all combinations of a plurality of dormant base stations that can manage neighboring cells of the connected cell of the user terminal that does not satisfy the quality of service as starting base station combination candidates,
Estimating the estimated radio quality information when starting a base station included in the start base station combination candidate,
Second load information of each active base station after predicting a change in the connected cell of the user terminal based on the estimated radio quality information and starting a base station included in the start base station combination candidate Get
Based on the estimated radio quality information, the first load information, and the second load information, calculate the service quality estimate value after starting the base station included in the start base station combination candidate,
Compare the service quality estimate when each of the activated base station combination candidates is activated, determine the activated base station combination candidate that satisfies the service quality estimated value and minimizes the number of activated base stations,
19. The base station control method according to appendix 18, wherein the start instruction is notified to all base stations included in the start base station combination candidate.
(Supplementary Note 21) When the activated base station candidate is activated, the estimated radio quality information is estimated, and when a change in the connected cell of the user terminal is predicted,
Estimating the estimated radio quality information with reference to the UE measurement information, the location information and a database registered in advance corresponding to the radio quality information of each cell measured at the location,
The base station according to any one of appendix 18 to appendix 20, wherein a change in a connected cell of the user terminal is predicted by determining the presence / absence of handover of the user terminal based on the estimated radio quality information Control method.
(Supplementary note 22) The base station control method according to any one of supplementary note 18 to supplementary note 21, wherein the service quality is a throughput or a transmission delay time of the user terminal.
(Supplementary note 23) The first load information includes the throughput of the user terminal connected to the connected cell, the number of user terminals connected to the connected cell, and a frequency block (Resource Block) usage rate,
Note that when determining whether or not there is a user terminal that does not satisfy a predetermined service quality, a throughput estimate value at the current time of the user terminal is calculated using the UE measurement information and the first load information as parameters. The base station control method according to any one of supplementary notes 18 to 21.
(Supplementary Note 24) The second load information is the number of user terminals connected to each of the activated base stations accompanying a change in the connected cell of the user terminal after activating the activated base station candidate,
In calculating the service quality estimation value of the user terminal after starting the startup base station candidate, the estimated radio quality information and the number of user terminals connected to the connected cell included in the first load information, the first 24. The base station control method according to appendix 23, wherein the load information of 2 and the frequency block usage rate are calculated as parameters.
(Additional remark 25) The presence or absence of the said user terminal which is not satisfy | filling predetermined | prescribed service quality is triggered by having changed the load of the said connection cell by the predetermined period or the change of the number of user terminals. The base station control method according to any one of supplementary notes 18 to 24.
(Supplementary note 26)
From each of a plurality of base stations deployed in a predetermined area, first load information of the base station including an actual service quality measurement value of a user terminal having a cell managed by the base station as a connected cell, The user terminal that has received UE (User Equipment) measurement information reported by the user terminal to the base station, including location information and radio quality information of each cell measured at the location, and does not satisfy a predetermined service quality Service quality determination function means for determining the presence or absence of,
When the service quality determination function means determines that there is a user terminal that does not satisfy the service quality, a dormant base that can manage neighboring cells of the connected cell of the user terminal that does not satisfy the service quality A starting base station candidate selection function means for selecting a station as a starting base station candidate;
When the activated base station candidate is activated, radio quality information of each cell measured by the user terminal is estimated as estimated radio quality information, and a change in the connected cell of the user terminal is predicted based on the estimated radio quality information Radio quality information calculation function means for acquiring second load information of each of the activated base stations after activating the activated base station candidate;
Based on the estimated radio quality information, the first load information, and the second load information, a service quality estimate value of the user terminal after starting the activation base station candidate is calculated as a service quality estimate value. Service quality calculation function means,
A base station that selects any one of the activated base station candidates as a base station to be activated based on the service quality estimation value, and notifies the selected base station of an activation instruction for shifting from an inactive state to an activated state A program for functioning as a start notification function means.
(Additional remark 27) The said base station starting notification function means compares the said service quality estimated value at the time of starting each said starting base station candidate, The said starting base station candidate from which the minimum value of the said service quality estimated value becomes the maximum 27. The program according to appendix 26, wherein the program is selected as a base station to be activated.
(Additional remark 28) The said starting base station candidate selection function means makes all the combinations of the several dormant base station which can manage the periphery cell of the connection cell of the said user terminal which does not satisfy the said quality of service start base station Select as a combination candidate,
The radio quality information calculation function means estimates the estimated radio quality information when a base station included in the activated base station combination candidate is activated, and changes in connected cells of the user terminal based on the estimated radio quality information And obtaining the second load information of each of the activated base stations after starting the base stations included in the activated base station combination candidates,
The service quality calculation function means, based on the estimated radio quality information, the first load information, and the second load information, the service quality after starting a base station included in the start base station combination candidate Calculate an estimate,
The base station activation notification function means compares the service quality estimated values when the activated base station combination candidates are activated, satisfies the service quality estimated values, and activates the number of activated base stations to be minimum. 27. The program according to appendix 26, wherein a base station combination candidate is selected, and the start instruction is notified to all base stations included in the selected start base station combination candidate.
(Supplementary Note 29) The radio quality information calculation function means refers to the UE measurement information, a location information and a database registered in advance in association with radio quality information of each cell measured at the location. Supplementary note 26 to supplementary note 28, wherein the estimated wireless quality information is estimated, a change in the connected cell of the user terminal is predicted by determining the presence / absence of handover of the user terminal based on the estimated wireless quality information A program as described in one of the supplementary notes.
(Supplementary note 30) The program according to any one of supplementary notes 26 to 29, wherein the service quality is a throughput or a transmission delay time of the user terminal.
(Supplementary Note 31) The first load information includes a throughput of the user terminal connected to the connected cell, a number of user terminals connected to the connected cell, and a frequency block (Resource Block) usage rate,
The service quality calculation function means calculates a current throughput estimation value of the user terminal using the UE measurement information and the first load information as parameters, and the service quality determination function means is based on the service quality calculation function means. The program according to any one of supplementary notes 26 to 29, wherein the presence / absence of the user terminal that does not satisfy a predetermined service quality is determined using the calculation result.
(Supplementary Note 32) The second load information is the number of user terminals connected to each of the activated base stations in accordance with a change in the connected cell of the user terminal after activating the activated base station candidate,
The service quality calculation function means uses the estimated radio quality information, the number of user terminals connected to the connected cell included in the first load information, the second load information, and the frequency block usage rate as parameters. The program according to supplementary note 31, wherein the service quality estimation value of the user terminal after the activation base station candidate is activated is calculated.
(Additional remark 33) The said service quality determination function means is the presence or absence of the said user terminal which does not satisfy predetermined service quality triggered by the load of the said connection cell having changed by the predetermined period or the change of the number of user terminals. The program according to any one of supplementary notes 26 to 32, wherein the program is determined.

1, 2, 3 Mobile communication system 10, 100 Base station controller 20, 20-1, 20-2, 20-3, 20-4 Base station 21 Main base station 22-1, 22-2, 22-3 Sub Base station 30-1, 30-2, 30-3, 30-4 Radio cell (cell)
31, 32-1, 32-2, 32-3 Cell 40, 40-1, 40-2, 40-3 User terminal (UE)
DESCRIPTION OF SYMBOLS 11 Activation base station selection means 12 Radio quality information calculation means 13 Service quality calculation means 201 Base station operation means 202 Activation control means 31 CPU
32 Main storage unit 33 Auxiliary storage unit 34 Communication control unit 35 Display unit 36 Input unit 37 System bus 101, 211 Activation base station selection unit 102, 212 Radio quality information calculation unit 103, 213 Service quality calculation unit 104, 214 UE measurement information Database 1011, 2111 Service quality determination unit 1012, 2112 Activation base station candidate selection unit 1013, 2113 Base station activation notification unit 301 Service quality determination function means 302 Activation base station candidate selection function means 303 Radio quality information calculation function means 304 Service quality calculation Function means 305 Base station activation notification function means

Claims (10)

From each of a plurality of base stations deployed in a predetermined area, first load information of the base station including an actual service quality measurement value of a user terminal having a cell managed by the base station as a connected cell, The user terminal that has received UE (User Equipment) measurement information reported by the user terminal to the base station, including location information and radio quality information of each cell measured at the location, and does not satisfy a predetermined service quality An activation base station selection means for selecting a dormant base station that can manage a neighboring cell of a connection cell of the user terminal that does not satisfy the quality of service as an activation base station candidate;
When the activated base station candidate is activated, radio quality information of each cell measured by the user terminal is estimated as estimated radio quality information, and a change in the connected cell of the user terminal is predicted based on the estimated radio quality information Radio quality information calculation means for acquiring second load information of each of the activated base stations after activating the activated base station candidate;
Based on the estimated radio quality information, the first load information, and the second load information, a service quality estimate value of the user terminal after starting the activation base station candidate is calculated as a service quality estimate value. Service quality calculation means;
With
The activated base station selecting means selects one of the activated base station candidates as a base station to be activated based on the service quality estimation value, and causes the selected base station to shift from an inactive state to an activated state A base station control device that notifies an activation instruction. The activation base station selection means compares the service quality estimation values when the activation base station candidates are activated, and a base to activate the activation base station candidate that has a minimum minimum service quality estimation value. The base station control device according to claim 1, wherein the base station control device is selected as a station. The activation base station selection means selects all combinations of a plurality of dormant base stations that can manage neighboring cells of the connected cell of the user terminal that does not satisfy the quality of service as activation base station combination candidates,
The radio quality information calculation means estimates the estimated radio quality information when a base station included in the activated base station combination candidate is activated, and changes a connection cell of the user terminal based on the estimated radio quality information. Predicting and obtaining the second load information of each of the activated base stations after activating the base stations included in the activated base station combination candidates,
The service quality calculation means, based on the estimated radio quality information, the first load information, and the second load information, the service quality estimation after starting a base station included in the start base station combination candidate Calculate the value
The activation base station selection unit compares the service quality estimation values when the activation base station combination candidates are activated, satisfies the service quality estimation value and minimizes the number of base stations to be activated. The base station control apparatus according to claim 1, wherein a station combination candidate is selected, and the activation instruction is notified to all base stations included in the selected activation base station combination candidate. The radio quality information calculating means refers to the estimated radio quality information with reference to the UE measurement information, location information and a database registered in advance in association with radio quality information of each cell measured at the location. And predicting a change in a connected cell of the user terminal by determining whether or not the user terminal is handed over based on the estimated radio quality information. The base station control apparatus according to claim. The first load information includes a throughput of the user terminal connected to the connected cell, a number of user terminals connected to the connected cell, and a frequency block (Resource Block) usage rate measured by the base station,
The service quality calculation unit calculates a current throughput estimate of the user terminal using the UE measurement information and the first load information as parameters, and the activation base station selection unit calculates the calculation by the service quality calculation unit. The base station control apparatus according to any one of claims 1 to 4, wherein presence or absence of the user terminal that does not satisfy a predetermined service quality is determined using a result. The second load information is the number of user terminals connected to each of the activated base stations accompanying a change in the connected cell of the user terminal after activating the activated base station candidate,
The service quality calculation means uses the estimated radio quality information, the number of user terminals connected to the connected cell included in the first load information, the second load information, and the frequency block usage rate as parameters. 6. The base station control apparatus according to claim 5, wherein the service quality estimation value of the user terminal after starting a base station candidate is calculated. A plurality of base stations arranged in a predetermined area, and a base station controller for controlling the plurality of base stations,
The base station control device according to any one of claims 1 to 6, wherein the base station control device is a base station control device.
Each of the plurality of base stations is
Report the first load information of the base station including the measured value of the service quality of the user terminal whose cell is the cell managed by the base station and the UE measurement information reported by the user terminal to the base station controller. Base station operating means to
A mobile communication system, comprising: a start control unit that starts a predetermined apparatus operation during suspension when receiving the start instruction notification from the base station control apparatus. A first base station and a plurality of second base stations arranged in a predetermined area;
The first base station is
The load information of the first base station including the measured value of the service quality of the user terminal having the cell managed by the first base station as the connection cell and the cell managed by the second base station as the connection cell The first load information, which is the load information of the second base station including the measured value of the service quality of the user terminal, the position information of the user terminal reported to the first base station, and the measured position. UE (User Equipment) measurement information including radio quality information of each cell and the UE measurement information reported to the second base station, and whether there is a user terminal that does not satisfy a predetermined service quality Service quality determination means for determining;
When the service quality determination means determines that there is the user terminal that does not satisfy the service quality, the second idle terminal that can manage the neighboring cells of the connected cell of the user terminal that does not satisfy the service quality A starting base station candidate selecting means for selecting the base station as a starting base station candidate;
When the activated base station candidate is activated, radio quality information of each cell measured by the user terminal is estimated as estimated radio quality information, and a change in the connected cell of the user terminal is predicted based on the estimated radio quality information Radio quality information calculation means for acquiring second load information of each of the activated base stations after activating the activated base station candidate;
Based on the estimated radio quality information, the first load information, and the second load information, a service quality estimate value of the user terminal after starting the activation base station candidate is calculated as a service quality estimate value. Service quality calculation means;
Based on the service quality estimation value, select one of the activated base station candidates as a base station to be activated, and notify the selected second base station of an activation instruction for shifting from an inactive state to an activated state Each of the plurality of second base stations includes:
The first load information of the second base station including the measured value of the service quality of the user terminal having the cell managed by the second base station as a connected cell and the UE measurement information reported by the user terminal Base station operating means for reporting to the first base station;
A mobile communication system, comprising: an activation control unit that activates a predetermined apparatus operation during suspension when receiving the activation instruction notification from the first base station. From each of a plurality of base stations deployed in a predetermined area, first load information of the base station including an actual service quality measurement value of a user terminal having a cell managed by the base station as a connected cell, The user who has received UE (User Equipment) measurement information reported by the user terminal to the base station, including location information and radio quality information of each cell measured at the location, and does not satisfy a predetermined service quality Determine the presence of a device,
When it is determined that there is the user terminal that does not satisfy the service quality, a dormant base station that can manage a neighboring cell of a connection cell of the user terminal that does not satisfy the service quality is set as a starting base station candidate. Selected,
When the activated base station candidate is activated, radio quality information of each cell measured by the user terminal is estimated as estimated radio quality information, and a change in the connected cell of the user terminal is predicted based on the estimated radio quality information And obtaining the second load information of each of the activated base stations after activating the activated base station candidate,
Based on the estimated radio quality information, the first load information, and the second load information, a service quality estimate value of the user terminal after starting the startup base station candidate is calculated as a service quality estimate value. ,
Based on the service quality estimation value, selecting any one of the activated base station candidates as a base station to be activated, and notifying the selected base station of an activation instruction for shifting from an inactive state to an activated state A base station control method. Computer
From each of a plurality of base stations deployed in a predetermined area, first load information of the base station including an actual service quality measurement value of a user terminal having a cell managed by the base station as a connected cell, The user terminal that has received UE (User Equipment) measurement information reported by the user terminal to the base station, including location information and radio quality information of each cell measured at the location, and does not satisfy a predetermined service quality Service quality determination function means for determining the presence or absence of,
When the service quality determination function means determines that there is a user terminal that does not satisfy the service quality, a dormant base that can manage neighboring cells of the connected cell of the user terminal that does not satisfy the service quality A starting base station candidate selection function means for selecting a station as a starting base station candidate;
When the activated base station candidate is activated, radio quality information of each cell measured by the user terminal is estimated as estimated radio quality information, and a change in the connected cell of the user terminal is predicted based on the estimated radio quality information Radio quality information calculation function means for acquiring second load information of each of the activated base stations after activating the activated base station candidate;
Based on the estimated radio quality information, the first load information, and the second load information, a service quality estimate value of the user terminal after starting the activation base station candidate is calculated as a service quality estimate value. Service quality calculation function means,
A base station that selects any one of the activated base station candidates as a base station to be activated based on the service quality estimation value, and notifies the selected base station of an activation instruction for shifting from an inactive state to an activated state A program for functioning as a start notification function means.

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