Power-save operation supporting apparatus, power-save operation supporting method, storage medium and base station

The present invention relates to a power saving operation support device, a power saving operation support method, a recording medium, and a base station.

In the case of the current radio access network, the base station is usually always in operation, and the transmission output of the pilot channel is kept constant. Therefore, for example, if there are no mobile stations in the coverage area of the base station, or if the number of mobile stations is small, power is wasted. On the other hand, there is a demand for a wireless access network that consumes less power in order to respond to environmental problems that are advancing on a global scale. As an example of the technique for meeting this demand, for example, the techniques described in Patent Document 1 and Patent Document 2 can be mentioned. In Patent Document 1, the own base station measures the received power and the traffic amount from the peripheral base station, and when the traffic amount of the peripheral base station is low and the received power satisfies the required quality, it depends on the load of the own base station. The method of reducing the transmission power and finally stopping the power is disclosed. On the other hand, in Patent Document 2, when the traffic is reduced, the transmission output of one central base station is increased, and transmission is stopped for the base stations adjacent to the base station so that the entire system can be received. A method for reducing power consumption will be disclosed.

<p num="0003"><patcit num="1"><text>Japanese Unexamined Patent Publication No. 2003-37555</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 7-170566</text></patcit></p>

<p num="0004"><nplcit num="1"><text>A.Wacker, K.Sipila, A.Kuurne, Automated and remotely optimization of antenna subsystem based on radio network performance, The 5th International Symposium on Wireless Personal Multimedia Communications (WPMC), vol.2, pp.752-756, Oct.2002.</text></nplcit></p>

<p num="0005"> By the way, in order to maintain good service quality in the coverage area of a wireless base station, it is required that the quality at each evaluation point in the coverage area satisfies a predetermined standard. However, in the case of the methods described in Patent Document 1 and Patent Document 2, the influence of the power saving control on the cover area is not taken into consideration when selecting the base station to be controlled by the power saving. Therefore, there is a possibility that an area below a predetermined service quality standard may occur due to power saving control. Specifically, in the case of Patent Document 1, the suspension is determined based on the measurement information based on the fact that the own base station is within the coverage area of another base station. When the coverage area of the own base station and the other base station overlaps only partially, the other base station does not consider the area covered only by the own base station. Therefore, in the case of Patent Document 1, there may be an area where the service quality does not meet the predetermined quality. Further, in the case of Patent Document 2, the stop base station is selected only according to the traffic volume without considering the influence on the coverage area after the stop of the own base station. Therefore, when the propagation environment is complicated, there may be an area where the service quality deteriorates only by controlling the transmission power of the central base station. The present invention has been made to solve the above problems, and is a power-saving operation support device capable of reducing the power consumption of a radio access network while suppressing the occurrence of areas where service quality deteriorates. The purpose is to provide power operation support methods, storage media, and base stations.</p>

<p num="0006"> In order to solve the above-mentioned problems, the power-saving operation support device of the present invention determines the degree of deterioration of service quality when power-saving control is performed on an arbitrary base station, and the degree of deterioration is predetermined. In the case of the following criteria, the base station is provided with a selection means for selecting the base station as a candidate base station for performing power saving control. Further, the power saving operation support method of the present invention estimates the degree of deterioration of service quality when power saving control is performed on an arbitrary base station, and when the degree of deterioration is equal to or less than a predetermined standard, the base station. Is selected as a candidate base station for implementing power saving control. Further, the storage medium of the present invention has a process of estimating the degree of deterioration of service quality when power saving control is performed on an arbitrary base station, and when the degree of deterioration is equal to or less than a predetermined reference, the base station is used. , Stores the power saving operation support program that causes the computer to execute the process of selecting as a candidate base station for performing power saving control. Further, the base station of the present invention is at least one base station among a plurality of base stations capable of performing power saving control, and is a service when power saving control is performed on the own base station. An estimation means for estimating the degree of deterioration in quality, an acquisition means for acquiring the estimation result of the degree of deterioration in service quality when power saving control is performed on another base station from another base station, and the own and others. It is provided with a selection means for selecting a candidate base station for performing power saving control from its own base station and other base stations based on the degree of deterioration of the service quality of the base station.</p>

<p num="0007"> According to the present invention, it is possible to reduce the power consumption of the radio access network while suppressing the occurrence of areas where the service quality deteriorates.</p>

<figref num="1">It is a block diagram which shows the structural example of the mobile communication system which includes the power saving operation support device which concerns on 1st Embodiment of this invention.</figref><figref num="2">It is a block diagram which shows the configuration example of the network monitoring device and the power saving operation support device shown in FIG.</figref><figref num="3">This is a table showing an example of traffic information stored in the traffic information storage unit shown in FIG.</figref><figref num="4">This is a table showing an example of base station information stored in the base station information storage unit shown in FIG.</figref><figref num="5">It is a table showing an example of the service quality information stored in the service quality information storage unit shown in FIG.</figref><figref num="6">It is a flowchart for demonstrating the operation example (operation example about selection of a candidate base station) of the power saving operation support apparatus shown in FIG.</figref><figref num="7">It is a flowchart for demonstrating the operation example (operation example about the estimation of the degree of deterioration of service quality) of the power saving operation support device shown in FIG.</figref><figref num="8">It is a conceptual diagram for demonstrating the evaluation example of the degree of deterioration of service quality in 1st Embodiment, (a) shows the initial state, (b) shows the state which stopped a predetermined base station, and (c) shows the state in which the radio parameters of the peripheral base stations have been changed.</figref><figref num="9">It is a flowchart for demonstrating the operation example (operation example about the estimation of the degree of deterioration of service quality) of the power saving operation support apparatus of 2nd Embodiment of this invention.</figref><figref num="10">It is a flowchart for demonstrating the operation example (operation example about selection of a candidate base station) of the power saving operation support apparatus of 3rd Embodiment of this invention.</figref><figref num="11">It is a block diagram which shows the structural example of the power saving operation support apparatus of 4th Embodiment of this invention.</figref><figref num="12">It is a table which shows an example of the weighting information stored in the map information storage part shown in FIG.</figref><figref num="13">It is a flowchart for demonstrating the operation example (operation example about the estimation of the degree of deterioration of service quality) of the power saving operation support apparatus shown in FIG.</figref><figref num="14">It is a figure which shows an example of the weighting process of the evaluation point in the power saving operation support apparatus shown in FIG.</figref><figref num="15">It is a flowchart for demonstrating the operation example (operation example about selection of a candidate base station) of the power saving operation support apparatus of 5th Embodiment of this invention.</figref><figref num="16">It is a block diagram which shows the structural example of the power saving operation support apparatus of 6th Embodiment of this invention.</figref><figref num="17">It is a flowchart for demonstrating the operation example (operation example about selection of a candidate base station) of the power saving operation support apparatus shown in FIG.</figref><figref num="18">It is a conceptual diagram for demonstrating the evaluation example of the power saving effect in 6th Embodiment, (a) shows the power consumption in the initial state (the state before the base station # 1 is stopped), and ( b) shows the power consumption after the power saving control is implemented (the state after the base station # 1 is stopped).</figref><figref num="19">It is a block diagram which shows the structural example of the base station which concerns on 7th Embodiment of this invention.</figref>

[First Embodiment] FIG. 1 is a block diagram showing a configuration example of a mobile communication system including the power saving operation support device 101 according to the first embodiment of the present invention. The network monitoring device 100 is connected to the mobile communication core network 102 via a wired link 110. The mobile communication core network 102 is connected to the external network 104. Further, the network monitoring device 100 is connected to the wireless access network 103 via the wired link 111. The radio access network 103 includes a plurality of base stations 120 to 122. Each base station 120-122 communicates with at least one mobile station 130. The network monitoring device 100 monitors the communication status of the base stations 120 to 122 and transmits / receives control traffic. In addition, the network monitoring device 100 monitors radio parameters and service quality of each base station 120 to 122. The power saving operation support device 101 is connected to the network monitoring device 100 via a wired link 112. The power-saving operation support device 101 selects a base station capable of performing power-saving control while suppressing the occurrence of areas where service quality deteriorates as much as possible, and saves such as changing wireless parameters including base stations around the base station. Outputs power control information to support power saving operations. Specifically, the power saving operation support device 101 estimates the degree of deterioration of service quality after the power saving control is implemented, and selects a candidate base station for performing the power saving control. The above-mentioned "deteriorated area" may be hereinafter referred to as a "deteriorated area". FIG. 2 is a block diagram showing a configuration example of the network monitoring device 100 and the power saving operation support device 101 shown in FIG. The network monitoring device 100 includes a traffic information storage unit 202 and a base station information storage unit 204. FIG. 3 is a table showing an example of the traffic information 300 stored in the traffic information storage unit 202 shown in FIG. In this case, the traffic information 300 defines a radio base station ID (Identification) 301, a radio cell ID 302, a number of calls 303, a call volume 304, and a number of mobile stations 305. FIG. 4 is a table showing an example of the base station information 320 stored in the base station information storage unit 204 shown in FIG. In this case, the base station information 320 defines the base station ID 301, the radio cell ID 302, the base station position 321, the radio cell cover area 322, the controlled radio cell cover area 323, the antenna parameter 324, and the power consumption 325. .. The power saving operation support device 101 includes a candidate base station selection unit 200 (selection means), a service quality estimation unit 201 (estimation means), and a service quality information storage unit 203. The candidate base station selection unit 200 inputs the service quality estimation result for each evaluation area from the service quality estimation unit 201. Further, the candidate base station selection unit 200 inputs the traffic information 300 and the base station information 320 from the network monitoring device 100. The candidate base station selection unit 200 uses the input information to estimate the degree of deterioration in service quality after power saving control including changes in radio parameters of peripheral base stations. Then, the candidate base station selection unit 200 selects a base station whose estimated deterioration degree is equal to or less than a predetermined threshold value as a candidate base station for performing power saving control. The degree of deterioration of the service quality is actually estimated by the service quality estimation unit 201 based on the request of the candidate base station selection unit 200. The service quality estimation unit 201 inputs the service quality information 310 from the service quality information storage unit 203. Further, the service quality estimation unit 201 inputs the traffic information 300 and the base station information 320 from the network monitoring device 100. Based on the request of the candidate base station selection unit 200, the service quality estimation unit 201 estimates the degree of deterioration of the service quality of each base station 120 to 122 using the input information. For example, the service quality estimation unit 201 compares the spatial size of the cover area of each base station satisfying a predetermined received electric field strength or signal-to-interference ratio before and after the implementation of power saving control, and estimates the degree of deterioration of the service quality. .. The service quality information 310 can be obtained from propagation estimation or actual measurement information. FIG. 5 is a table showing an example of the service quality information 310 stored in the service quality information storage unit 203 shown in FIG. The service quality information 310 is composed of the evaluation point quality information 317 and the cell quality information 318. In this case, the evaluation point 311, the received electric field strength 312, and the signal-to-interference ratio 313 are defined as the evaluation point quality information 317. Further, as the cell quality information 318, the base station ID 301, the radio cell ID 302, the average throughput 314, the number of handovers (denoted as HO in FIG. 5) 315, and the number of successful handovers 316 are specified. FIG. 6 is a flowchart for explaining an operation example (operation example for selecting a candidate base station) of the power saving operation support device 101. First, the candidate base station selection unit 200 selects one arbitrary base station from the unselected base station group (step S101). The candidate base station selection unit 200 uses the traffic information 300 input from the network monitoring device 100 to determine whether or not the traffic of the selected base station is equal to or less than a predetermined threshold value (step S102). If the traffic is not less than or equal to the threshold value (when the determination is "No" in step S102), the candidate base station selection unit 200 selects one other unselected base station in step S101. When the traffic is equal to or less than a predetermined threshold value (when the determination is Yes in step S102), the candidate base station selection unit 200 covers the peripheral base stations when the power saving control is performed on the selected base stations. A predetermined range that affects the service quality including the above is set as the evaluation area (step S103). Further, the candidate base station selection unit 200 estimates the degree of deterioration in service quality after performing power saving control on the selected base station (step S104). Specifically, the service quality estimation unit 201 estimates the degree of deterioration of the service quality. The details of estimating the degree of deterioration of service quality (in other words, the operation of the service quality estimation unit 201) will be described later. The candidate base station selection unit 200 determines whether or not the degree of deterioration of the service quality after the execution of the power saving control is equal to or less than a predetermined threshold value (step S105). When the degree of deterioration of service quality is not equal to or less than a predetermined threshold value (when the determination is No in step S105), the candidate base station selection unit 200 selects one other unselected base station in step S101. When the degree of deterioration of service quality is equal to or less than a predetermined threshold value (when "Yes" is determined in step S105), the candidate base station selection unit 200 selects the selected base station as a candidate base station for implementing power saving control. (Step S106). Perform the same processing for all base stations, and unselected base stations When the selection of is completed (in the case of selection completed in step S101), the operation of the candidate base station selection unit 200 ends. In this case, information on candidate base stations (groups) for implementing power saving control is extracted, and power saving control is executed based on the information. FIG. 7 is a flowchart for explaining an operation example (operation example for estimating the degree of deterioration of service quality) of the power saving operation support device 101. First, the service quality estimation unit 201 selects one evaluation point arranged in a grid pattern within the evaluation area (a predetermined range that affects the service quality including the coverage area of the peripheral base station) (step S201). The service quality estimation unit 201 estimates the received electric field strength at the selected evaluation point (step S202). The service quality estimation unit 201 determines whether or not the estimated received electric field strength is equal to or less than a predetermined threshold value (step S203). If the estimated received electric field strength is not less than or equal to a predetermined threshold (when the determination is "No" in step S203), the service quality estimation unit 201 selects another evaluation point in step S201. When the estimated received electric field strength is equal to or less than a predetermined threshold value (when the determination is Yes in step S203), the service quality estimation unit 201 determines whether or not a peripheral base station is selected for the evaluation point (when the determination is Yes). Step S204). When the peripheral base stations are not selected (when the determination is Yes in step S204), the service quality estimation unit 201 uses the position information 321 of each base station input from the base station information storage unit 204 to evaluate the evaluation points. Calculate the physical distance from to each base station (step 205). Further, based on the calculation result, a predetermined number of base stations are selected as peripheral base stations in ascending order of physical distance (step S206). Then, the service quality estimation unit 201 changes the radio parameters of the peripheral base stations in order to reduce the service quality deterioration points generated by the power saving control (step S207). Similarly, the service quality estimation unit 201 estimates the received electric field strength after the power saving control is implemented for each evaluation point, and changes the radio parameters of the peripheral base stations to improve the service quality. When the peripheral base station of the evaluation point has been selected (when "No" is determined in step S204), the service quality estimation unit 201 extracts it as a service quality deterioration point where the service quality cannot be improved even by changing the radio parameters of the peripheral base station. (Step S208). Finally, the service quality deterioration points before and after the implementation of the power saving control are compared, and the degree of service quality deterioration is estimated (step S209). The estimation result of the degree of service quality deterioration is handed over to the candidate base station selection unit 200. This completes the estimation of the degree of service quality deterioration. Regarding the process of step S207, the radio parameters include, for example, the antenna tilt angle, the transmission power, the handover parameters, and the like. The radio parameters are changed based on a predetermined algorithm. As for the predetermined algorithm, for example, the control of the antenna tilt angle is well known to those skilled in the art as shown in Non-Patent Document 1, and therefore the description thereof will be omitted. Further, regarding the process of step S202, the signal to interference ratio can be used instead of the received electric field strength. Further, regarding the process of step S205, "path loss" can be used instead of "physical distance". In this case, in the process of step S206, from the process of "selecting a predetermined number of base stations as peripheral base stations in ascending order of physical distance", "selecting a base station whose path loss is equal to or less than a predetermined threshold value as peripheral base stations". It is changed to processing. FIG. 8 is a conceptual diagram showing an evaluation example of the degree of deterioration of service quality in the first embodiment. As an initial state, the states in which base stations 120, 121, and 122 are in operation are shown (see FIG. 8 (a)). Here, the coverage areas of the base stations 120, 121, and 122 are A120, A121, and A122, respectively. Hereinafter, for example, the case of estimating the service quality when the base station 120 is stopped will be taken as an example (see FIG. 8 (b)). Here, the area where the service quality has deteriorated is referred to as D120 (shown by diagonal lines in FIG. 8 (b)). To improve the quality of service (ie, to eliminate or reduce the D120), change the radio parameters of the peripheral base stations (see Figure 8 (c)). At this time, the degree of deterioration of service quality cannot be covered even by changing the radio parameters of the peripheral base stations, and the spatial size of the service quality deterioration area D120 (the area shown by diagonal lines in FIG. 8 (c)). It is calculated from the size of). In the case of the first embodiment described above, a base station having a small degree of deterioration in service quality after power saving control is executed is selected as a candidate base station for power saving control. Therefore, it is possible to reduce the power consumption of the wireless access network while suppressing the occurrence of areas where the service quality deteriorates. Further, in the above description, base stations whose traffic exceeds the threshold value are excluded from the candidate base stations (see step S102 in FIG. 6). Therefore, it is possible to simplify the power saving operation support process and avoid performing the power saving control for the base station that does not need (or should not) save the power. Of course, the process of excluding base stations whose traffic exceeds the threshold value from the candidate base stations (in other words, the process of determining whether or not a base station has traffic below the threshold value as a candidate base station) is not always required. Not required. That is, even if all base stations are targeted regardless of the level of traffic, it is possible to reduce the power consumption of the radio access network while suppressing the occurrence of areas where the service quality deteriorates. [Second Embodiment] Hereinafter, the power saving operation support device according to the second embodiment of the present invention will be described. The configuration of the mobile communication system to which this power saving operation support device belongs is the same as that of the mobile communication system shown in FIG. The configuration of this power saving operation support device is the same as that of the power saving operation support device 101 shown in FIG. Therefore, these explanations will be omitted. The difference of this power saving operation support device from the power saving operation support device 101 of the first embodiment is part of its operation. This will be described below. FIG. 9 is a flowchart for explaining an operation example (operation example for estimating the degree of deterioration of service quality) of the power-saving operation support device according to the second embodiment of the present invention. This operation is basically the same as the operation of the power saving operation support device 101 of the first embodiment shown in FIG. However, FIG. 7 and FIG. 9 differ in the following points. In FIG. 7, the received electric field strength at the selected evaluation point is estimated (step S202) and compared with the threshold value for the received electric field strength (step S203). On the other hand, in FIG. 9, the throughput at the selected evaluation point is estimated (step S211) and compared with the threshold value related to the throughput (step S212). That is, in the first embodiment, the degree of deterioration of the service quality after the implementation of the power saving control is evaluated by the spatial size of the area where the received electric field strength is low, whereas in the second embodiment, the service quality is evaluated. It differs in that the degree of deterioration is evaluated by the spatial size of the area where the throughput is low. In the case of the second embodiment described above, throughput is used as an evaluation index of the degree of deterioration of service quality after power saving control is implemented. Therefore, even in a communication environment that handles packet data, it is possible to reduce the power consumption of the radio access network while suppressing the occurrence of areas where the service quality deteriorates. [Third Embodiment] Hereinafter, the power saving operation support device according to the third embodiment of the present invention will be described. The configuration of the mobile communication system to which this power saving operation support device belongs is the same as that of the mobile communication system shown in FIG. The configuration of this power saving operation support device is the same as that of the power saving operation support device 101 shown in FIG. Therefore, these explanations will be omitted. The difference of this power saving operation support device from the power saving operation support device 101 of the first embodiment is part of its operation. This will be described below. FIG. 10 is a flowchart for explaining an operation example (operation example for selecting a candidate base station) of the power saving operation support device according to the third embodiment of the present invention. This operation is basically the same as the operation of the power saving operation support device 101 of the first embodiment shown in FIG. However, in the case of the present embodiment, when the degree of deterioration of the service quality is equal to or less than a predetermined threshold value (when the determination is Yes in step S105 of FIG. 10), the wireless transmission unit of the selected base station is stopped as power saving control. Control (step S111) is performed. The effect of the third embodiment described above will be described. In general, it is known that the power consumption of a base station can be fixedly reduced regardless of the presence or absence of a transmission signal by controlling the stop of the wireless transmission unit. In the case of the present embodiment, since the stop control of the wireless transmission unit of the selected base station is included as a part of the power saving control, the power saving effect of the radio access network can be further improved. [Fourth Embodiment] FIG. 11 is a block diagram showing a configuration example of the power saving operation support device 402 according to the fourth embodiment of the present invention. The power saving operation support device 402 further includes a weighting setting unit 400 (weighting setting means) and a map information storage unit 401 in addition to the configuration of the power saving operation support device 101 of the first embodiment shown in FIG. FIG. 12 is a table showing an example of the weighted information 410 stored in the map information storage unit 401. The weighting information 410 includes map information 415 and weight setting information 416. In map information 415, land attribute 412 and building attribute 413 that can be obtained from information such as road information, building information, river information, altitude information, land use classification, and population density are defined for each evaluation point 411. The weighting setting unit 400 sets the weight for the evaluation point in consideration of the preset degree of influence on the user such as the public nature of the building. Specifically, the weight setting unit 400 creates the weight setting information 416 (see FIG. 12) in the weight information 410. Regarding the weight set here, the same value may be set for each evaluation area, or a different value may be set for each evaluation point included in the evaluation area. FIG. 13 is a flowchart for explaining an operation example (operation example for estimating the degree of deterioration of service quality) of the power saving operation support device 402 shown in FIG. In the fourth embodiment, the operation of the entire power saving operation support is the same as the operation of the first embodiment shown in FIG. 6, and thus the description thereof is omitted here. The difference from FIG. 7 (first embodiment) of FIG. 13 (fourth embodiment) is further shown in FIG. 13 for weighting processing (step) for the extracted service quality deterioration point (extracted in step S208). The point is that S221) is added. Specifically, the weighting process here is performed in cooperation with the service quality estimation unit 201, the weighting setting unit 400, and the map information storage unit 401. FIG. 14 is a diagram showing an example of weighting processing of evaluation points in the power saving operation support device 402 shown in FIG. First, the weighting setting unit 400 divides the map into a grid of predetermined sizes (X1Y1, X2Y2, ... In FIG. 14), and the evaluation points (marked with a circle in FIG. 14) are in the center of the grid. ) Is set. Next, the weight setting unit 400 uses the land attribute 412 obtained from the map information 415 (see FIG. 12), the building attribute 413, and the weight 414 preset for each land attribute to weight the evaluation points (in FIG. 14). (Indicated by the number in the circle) is set. For example, when the service quality deteriorates, the weight value of the evaluation point having a large influence on the user is set large. The service quality estimation unit 201 multiplies the value of this weight by the spatial size of the area where the service quality has deteriorated, and uses it for evaluating the degree of deterioration of the service quality. Here, when power saving control is performed on the base station x, the area of the grid including the evaluation point i whose service quality has deteriorated is Si, and the weight of the evaluation point is Wi. Then, assuming that the degree of deterioration of service quality is Dx, the degree of deterioration when deterioration is performed at n + 1 (i = 0 to n) evaluation points in the evaluation area can be evaluated by (Equation 1). (Equation 1)<img id="000002" he="21" wi="46" file="JP5962013B2_D0001.tif" img-format="tif" img-content="drawing" /> In the fourth embodiment described above, not only the spatial size of the service quality but also the service quality can be correctly evaluated by performing the weighting process for the area in consideration of the degree of influence on the user. That is, by selecting a base station that implements power saving control in consideration of the degree of influence on the user, the degree of deterioration of service quality can be further suppressed. In the above description, as an example of applying the fourth embodiment (that is, a configuration in which the degree of deterioration of service quality is calculated in consideration of the weight of the evaluation point), the case where the fourth embodiment is applied to the first embodiment. Was given as an example. However, the fourth embodiment may be applied to each of the second or third embodiments described above, or to an embodiment in which at least two of the first to third embodiments are combined. it can. [Fifth Embodiment] Hereinafter, the power saving operation support device according to the fifth embodiment of the present invention will be described. The configuration of the mobile communication system to which this power saving operation support device belongs is the same as that of the mobile communication system shown in FIG. The configuration of this power saving operation support device is the same as that of the power saving operation support device 101 shown in FIG. Therefore, these explanations will be omitted. The difference of this power saving operation support device from the power saving operation support device 101 of the first embodiment is part of its operation. This will be described below. FIG. 15 is a flowchart for explaining an operation example (operation example for selecting a candidate base station) of the power saving operation support device according to the fifth embodiment of the present invention. This operation is basically the same as the operation of the power saving operation support device 101 of the first embodiment shown in FIG. Here, in the first embodiment, when the selection of the unselected base station is completed (in the case of selection completed in step S101), the operation of the candidate base station selection unit 200 ends. On the other hand, in the case of the fifth embodiment, further additional processing (steps S121 to S123) is executed. Specifically, the candidate base station selection unit 200 selects a candidate base station having the minimum degree of deterioration in service quality from the candidate base station group (step S121). The candidate base station selection unit 200 notifies the network monitoring device 100 of the change information of the radio parameters of the corresponding base station and its peripheral base stations. Then, power saving control is implemented for the candidate base station having the minimum degree of deterioration in service quality (step S122). The processes of steps S121 and S122 are repeatedly executed until the degree of deterioration of the service quality of the coverage area of the entire radio access network becomes equal to or less than the predetermined threshold (or the traffic load of the entire wireless access network becomes equal to or more than the predetermined threshold). (Step S123). When there are a plurality of candidate base stations having the minimum degree of deterioration in service quality, they may be selected in ascending order of change in radio parameters of peripheral base stations. Further, when there are a plurality of candidate base stations in which the degree of change in the radio parameters of the peripheral base stations is the minimum, the selection may be made in descending order of the margin of change in the radio parameters. According to the fifth embodiment described above, by implementing the power saving control on the base station where the degree of deterioration of the service quality is the minimum, the power saving can be achieved without deteriorating the service quality of the entire radio access network as much as possible. It is possible. In the above description, the first embodiment is applied as an example of applying the fifth embodiment (that is, a configuration in which a candidate base station having the minimum degree of deterioration in service quality is selected from the candidate base station group). An example is given when it is applied to a form. However, the fifth embodiment may be applied to each of the second to fourth embodiments described above, or an embodiment in which at least two of the first to fourth embodiments are combined. it can. [Sixth Embodiment] FIG. 16 is a block diagram showing a configuration example of the power saving operation support device 501 according to the sixth embodiment of the present invention. The power saving operation support device 501 further includes a power saving effect calculation unit 500 (power saving effect calculation means) in addition to the configuration of the power saving operation support device 101 shown in FIG. The power saving effect calculation unit 500 calculates the amount of power consumption reduction using the base station information 320 input from the base station information storage unit 204. FIG. 17 is a flowchart for explaining an operation example (operation example for selecting a candidate base station) of the power saving operation support device 501 shown in FIG. This operation is basically the same as the operation of the power saving operation support device 101 of the first embodiment shown in FIG. Here, in the first embodiment, when the selection of the unselected base station is completed (in the case of selection completed in step S101), the operation of the candidate base station selection unit 200 ends. On the other hand, in the case of the sixth embodiment, further additional processing (steps S131 to S134) is executed. Specifically, the power saving effect calculation unit 500 calculates the power saving effect after implementing the power saving control including the change of the radio parameters of the peripheral base stations (for example, the change of the transmission power and the coverage area) for the candidate base station. (Step S131). Next, the candidate base station selection unit 200 selects the optimum candidate base station in consideration of the degree of deterioration of service quality and the power saving effect calculated by the power saving effect calculation unit 500 (step). S132). Power saving control is performed for the above-mentioned optimum candidate base station (step S133). The processes of steps S131 to S133 are repeatedly executed until the degree of deterioration of the service quality of the coverage area of the entire radio access network becomes equal to or less than the predetermined threshold (or the traffic load of the entire wireless access network becomes equal to or more than the predetermined threshold). (Step S134). Here, α is used for the power saving effect E and β is used for the degree of deterioration D of service quality as weighting coefficients common to all base stations. Furthermore, assuming that the power saving effect when power saving control is performed on the base station x is Ex and the degree of deterioration of service quality is Dx, the evaluation function f (x) related to the selection of the candidate base station is, for example, (Equation 2). ). Obtain the evaluation function for all base stations and select the largest candidate base station. The degree of deterioration of service quality Dx is (Equation 1), and the power saving effect Ex can be obtained for each by (Equation 3) described later. However, for the power saving effect E, the case where the own base station can be stopped without increasing the power consumption of the peripheral base stations is set to 1, and the case where the power saving control is not implemented is set to 0, and the normalized one is used. In addition, the degree of deterioration D of service quality is normalized by setting 1 when all the evaluation points in the evaluation area are deteriorated and 0 when there is no evaluation point to be deteriorated. (Equation 2) f (x) = αE_x-βD_x(α + β = 1) FIG. 18 is a conceptual diagram for explaining an evaluation example of the power saving effect in the sixth embodiment. In FIG. 18, (a) shows the power consumption in the initial state (the state before the base station # 1 described later is stopped), and (b) is after the power saving control is executed (the base station # 1 is stopped). The power consumption in the state after the operation) is shown. In other words, FIG. 18 shows an example of the state change of the power consumption of the candidate base station # 1 and its peripheral base stations # 0 and # 2. The power saving effect calculation unit 500 determines the power consumption reduction of the candidate base station (for example, base station # 1) and the power consumption due to the change of the radio parameters of the peripheral base stations (for example, base stations # 0 and # 2). The increase / decrease and the increase / decrease in power consumption due to the increase / decrease in traffic due to the increase / decrease in the coverage area of the peripheral base stations are also compared. As a result, the power saving effect is calculated. Here, in base stations 1, 2, 3, ..., N, the standby power when the wireless transmitter of the base station is stopped is set to Ws1, Ws2, Ws3, ..., Wsn, and when the base station is operating. Let the fixed power consumption be Wf1, Wf2, Wf3, ..., Wfn. Furthermore, the dynamic power consumption before the power saving control is implemented, which changes according to the traffic, is Wo1, Wo2, Wo3, ..., Won, and the dynamic power consumption after the power saving control is implemented is Wo1', Wo2', Wo3. ', ... Won'. For example, when power saving control is performed on a base station x having m peripheral base stations, the power saving effect Ex due to the power saving control can be expressed by (Equation 3). (Equation 3)<img id="000003" he="21" wi="88" file="JP5962013B2_D0001.tif" img-format="tif" img-content="drawing" /> The effect of the sixth embodiment described above will be described. In general power saving operation control, power saving control is performed only according to the traffic load and coverage area of only the own base station and peripheral base stations, so that the power saving effect of the entire radio access network cannot be evaluated. Therefore, if a plurality of base stations can be stopped without causing a large deterioration in service quality, it may not be possible to select a candidate base station having a high power saving effect. In the present embodiment, before the implementation of the power saving control, the power consumption reduced by the own base station due to the power saving control includes the increase / decrease in the power consumption due to the change of the radio parameters of the peripheral base stations, and is included in the candidate base station. Evaluate the power saving effect of each. As a result, a candidate base station having a high power saving effect can be selected, so that the power saving effect of the entire radio access network can be further improved. In the above description, the first embodiment is applied as an example of applying the sixth embodiment (that is, a configuration in which the optimum candidate base station is selected in consideration of the degree of deterioration of service quality and the power saving effect). An example is given when it is applied to a form. However, the sixth embodiment can be applied to each of the second to fifth embodiments described above, or an embodiment in which at least two of the first to fifth embodiments are combined. it can. In the first to sixth embodiments described above, the case where the power saving operation support device 101 (402, 501) is provided outside the mobile communication core network 102 is taken as an example. However, the power saving operation support device 101 (402, 501) can also be arranged in the mobile communication core network 102. In that case, the network monitoring device 100 may be inside or outside the mobile communication core network 102. Further, the power saving operation support device 101 (402, 501) and the network monitoring device 100 can be configured as one device. [7th Embodiment] FIG. 19 is a block diagram showing a configuration example of the base station 600 according to the seventh embodiment of the present invention. The base station 600 is at least one base station among a plurality of base stations capable of performing power saving control. The base station 600 includes an estimation unit 601 (estimation means), an acquisition unit 602 (acquisition means), and a selection unit 603 (selection means). The estimation unit 601 estimates the degree of deterioration in service quality when power saving control is performed on the own base station 600. The acquisition unit 602 acquires the estimation result of the degree of deterioration of the service quality when the power saving control is performed on the other base station 700 from one or more other base stations 700. The selection unit 603 selects a candidate base station for power saving control from the own base station 600 and the other base station 700 based on the degree of deterioration of the service quality of the own base station 600 and the other base station 700. .. The other base station 700 includes at least a configuration corresponding to the estimation unit 601 in the own base station 600 and a configuration in which the estimation result of the degree of deterioration of the service quality in the other base station 700 is transmitted to the own base station 600. .. In the case of the seventh embodiment described above, a base station having a small degree of deterioration in service quality after power saving control is executed is selected as a candidate base station for power saving control. Therefore, it is possible to reduce the power consumption of the base station while suppressing the occurrence of areas where the service quality deteriorates. The first to seventh embodiments described above can also be embodied as predetermined hardware, for example, a circuit. Further, the first to seventh embodiments described above can be controlled and operated by a computer circuit (for example, a CPU (Central Processing Unit)) (not shown) based on a control program. In that case, these control programs are stored in, for example, a power saving operation support device (or a network monitoring device), a storage medium inside the base station, or an external storage medium, and are read out and executed by the computer circuit. Will be done. Examples of the internal storage medium include a ROM (Read Only Memory) and a hard disk. Further, examples of the external storage medium include removable media and removable disks. Although the invention of the present application has been described above with reference to the embodiment, the invention of the present application is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made within the scope of the present invention in terms of the structure and details of the present invention. This application claims priority on the basis of Japanese Application Japanese Patent Application No. 2010-000148 filed on January 4, 2010 and incorporates all of its disclosures herein.

100 Network monitoring device 101, 402, 501 Power saving operation support device 102 Mobile communication core network 103 Radio Access Network 104 Extranet 110 ~ 112 Wired link 120 ~ 122 base station 130 mobile station 200 Candidate base station selection section 201 Quality of Service Estimator 202 Traffic information storage 203 Quality of Service Information Storage 204 Base station information storage 300 traffic information 301 Base station ID 302 wireless cell ID 303 Calls 304 Call volume 305 Number of mobile stations 310 Quality of service information 311 Evaluation points 312 Received electric field strength 313 Signal to interference ratio 314 Average Throughput 315 Number of handover attempts 316 Number of successful handovers 317 Evaluation point quality information 318 Cell quality information 320 Base station information 321 Base station location 322 Wireless cell cover area 323 Radio cell cover area after control 324 Antenna parameters 325 power consumption 400 Weighting setting unit 401 Map information storage 410 Weighting information 411 Evaluation points 412 Land attributes 413 Building attributes 414 weight 415 Map information 416 Weight setting information 500 Power Saving Effect Calculation Department 600 base station 601 Estimator 602 Acquisition Department 603 Selection 700 other base stations