Control device, control method, and program

Abstract

A control device, a control method, and a program for monitoring the status of a high-traffic cell and its surrounding cells in mobile communications, and performing pre-adjustment before the surrounding cells transition to the high-traffic cell, are provided. [Solution] The control device 100 includes a congested cell identification unit that identifies a congested cell where communication traffic is congested from multiple cells including cells with different frequencies, a source cell identification unit that identifies a cell from the multiple cells that has the same frequency as the congested cell and from which multiple user terminals currently located in the source cell are expected to move to an area covered by the congested cell, and a handover control unit that controls the multiple user terminals currently located in the source cell to more easily hand over to cells with frequencies different from those of the congested cell and the source cell.

Description

[Technical Field]

[0001] The present invention relates to a control device, a control method, and a program. [Background technology]

[0002] Patent Document 1 describes that "in a common area such as a suburban area, a terrestrial cell using the same frequency F1 as the large zone cell 10A and a terrestrial cell using a different frequency F2 are formed, and when a UE connected to the terrestrial cell using the same frequency F1 is located at the edge of the cell, the UE is given priority for handover to the terrestrial cell using the different frequency F2 rather than the large zone cell 10A, thereby avoiding the concentration of communication traffic on the large zone cell 10A." [Prior art document] [Patent Documents] [Patent Document 1] JP 2022-29785 A Summary of the Invention [Means for solving the problem]

[0003] According to one embodiment of the present invention, there is provided a control device. The control device may include a congested cell identification unit that identifies a congested cell where communication traffic is congested from a plurality of cells including cells with different frequencies. The control device may include a source cell identification unit that identifies a cell from the plurality of cells that uses the same frequency as the congested cell and from which a plurality of user terminals currently serving the congested cell are expected to move to an area covered by the congested cell as a source cell. The control device may include a handover control unit that controls a plurality of user terminals currently serving the source cell to more easily hand over to a cell with a different frequency from the congested cell and the source cell.

[0004] In the control device, the handover control unit may control to change parameters related to handover of the multiple user terminals residing in the source cell so that the multiple user terminals can easily hand over to the congested cell and a cell using a frequency different from that of the source cell. Any of the control devices may include an information acquisition unit that acquires performance information of each of the multiple cells. In any of the control devices, the congested cell identification unit may identify a cell determined to have congested communication traffic based on the performance information of the multiple cells as the congested cell.

[0005] Any of the control devices may include a storage unit that stores a learning model that receives performance information of a plurality of cells as an input and outputs at least one of a cell in which communication traffic is congested and a cell predicted to become congested among the plurality of cells. Any of the control devices may include an information acquisition unit that acquires performance information of each of the plurality of cells. In any of the control devices, the congested cell identification unit may identify the congested cell by inputting the performance information of the plurality of cells acquired by the information acquisition unit into the learning model.

[0006] In any of the control devices, the source cell identifying unit may identify the source cell based on changes in congestion states of communication traffic of the plurality of cells over time. In any of the control devices, when the congested cell identifying unit identifies a cell covering a station as the congested cell, the source cell identifying unit may identify a cell covering a station identified based on a connection relationship with the station covered by the congested cell as the source cell.

[0007] In any of the control devices, when the congested cell identification unit identifies a cell covering a station as the congested cell, the source cell identification unit may identify as the source cell a cell covering the station identified based on the connection relationship with the station covered by the congested cell and timetable information.

[0008] In any of the control devices, the source cell identification unit may identify as the source cell a cell covering an area identified based on the connection relationship of a main road to the area covered by the congested cell.

[0009] In any of the control devices, the handover control unit may control the radio base station generating the source cell to notify an idle user terminal located in an area covered by the source cell of cell reselection parameters that prioritize a cell using a frequency different from that of the source cell.

[0010] In any of the control devices, the handover control unit may change parameters related to handover of the multiple user terminals located in the source cell depending on the status of a cell group including the congested cell, the source cell, and one or more cells located between the congested cell and the source cell.

[0011] In any of the control devices, the handover control unit may determine a frequency that makes it easier to hand over the multiple user terminals located in the source cell, depending on the status of the cell group, and may control to change parameters related to handover of the multiple user terminals so that it is easier for the multiple user terminals to hand over to a cell using the determined frequency.

[0012] In any of the control devices, the handover control unit may determine the amount of change in parameters related to handover of the multiple user terminals located in the source cell, depending on the status of the cell group.

[0013] According to one embodiment of the present invention, there is provided a control method executed by a computer. The control method may include a congested cell identification step of identifying a congested cell where communication traffic is congested from a plurality of cells including cells of different frequencies. The control method may include a source cell identification step of identifying a cell from the plurality of cells that uses the same frequency as the congested cell and from which a plurality of user terminals currently serving the congested cell are expected to move into an area covered by the congested cell as a source cell. The control method may include a handover control step of performing control so as to facilitate handover of a plurality of user terminals currently serving the source cell to a cell of a different frequency from the congested cell and the source cell.

[0014] According to one embodiment of the present invention, there is provided a program for causing a computer to execute any one of the above control methods.

[0015] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions. [Brief explanation of the drawings]

[0016] [Figure 1] 1 shows a schematic diagram of an example of a system 10 including a control device 100. [Figure 2] 1 shows an example of control of a wireless communication service by the control device 100. [Figure 3] FIG. 1 is an explanatory diagram for explaining a conventional technique. [Figure 4] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 5] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 6] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 7] 1 illustrates an example of a starting state of an embodiment of the present invention. [Figure 8] 1 shows an example of control of a wireless communication service by the control device 100. [Figure 9] FIG. 1 is an explanatory diagram for explaining a conventional technique. [Figure 10] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 11] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 12] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 13] 1 shows an example of control of a wireless communication service by the control device 100. [Figure 14] FIG. 1 is an explanatory diagram for explaining a conventional technique. [Figure 15] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 16] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 17] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 18] 1 shows an example of control of a wireless communication service by the control device 100. [Figure 19] FIG. 1 is an explanatory diagram for explaining a conventional technique. [Figure 20] FIG. 1 is an explanatory diagram for explaining a conventional technique. [Figure 21] FIG. 1 is an explanatory diagram for explaining a conventional technique. [Figure 22] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 23] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 24] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 25] 1 shows an example of control of a wireless communication service by the control device 100. [Figure 26] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 27] 1 shows an example of control of a wireless communication service by the control device 100. [Figure 28]1 shows an example of control of a wireless communication service by the control device 100. [Figure 29] 1 illustrates an example of a state of an embodiment of the present invention. [Figure 30] 2 shows an example of a functional configuration of the control device 100. [Figure 31] 10 shows an example of a flow of processing by the control device 100. [Figure 32] 1 shows an example of a hardware configuration of a computer 1200 that functions as the control device 100. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0018] In mobile communications, when a terminal performs handover between different frequencies, the terminal's communication interruption time tends to be long. For this reason, mobility settings are often configured to facilitate handover between the same frequencies. For this reason, current mobility settings in mobile communications tend to cause a user terminal, once it has entered a certain frequency range, to continue using that frequency thereafter. As a result, certain frequencies tend to become congested, particularly in high-traffic cells where user terminals, etc., are concentrated, such as at stations and on train lines.

[0019] The control device 100 according to this embodiment has a configuration that contributes to solving such problems. For example, the control device 100 monitors the status of a high-traffic cell and its surrounding cells, and performs pre-adjustment before the surrounding cell transitions to the high-traffic cell. Specifically, for example, the control device 100 switches the target cell for handover and cell reselection of user terminals in the surrounding cell to a cell other than the frequency where congestion has occurred, and distributes the user terminals to other frequencies before they enter the high-traffic cell. In addition, the control device 100 performs pre-adjustment on a prediction basis by using AI (Artificial Intelligence) / ML (Machine Learning).

[0020] Fig. 1 schematically illustrates an example of a system 10 including a control device 100. In the example illustrated in Fig. 1, the system 10 includes a network 90. ​​In the example illustrated in Fig. 1, the system 10 includes a plurality of radio base stations 200.

[0021] The control device 100 may be connected to a network 90. ​​A plurality of radio base stations 200 may be connected to the network 90. ​​The control device 100 may be communicatively connected to each of the plurality of radio base stations 200. In the example shown in FIG. 1 , the control device 100 is communicatively connected to each of the plurality of radio base stations 200 via the network 90. ​​Each of the plurality of radio base stations 200 may form a cell 20.

[0022] The system 10 may provide a wireless communication service. The network 90 may constitute a RAN (Radio Access Network). The control device 100 may be arranged in an operation unit of the RAN. The network 90 may include a core network. In this case, the control device 100 may be arranged in the core network. Also, for example, an information processing infrastructure may be connected below the core network, and the radio base station 200 may be connected below the information processing infrastructure. In this case, the control device 100 may be connected to the information processing infrastructure. The control device 100 may be arranged in the information processing infrastructure.

[0023] The system 10 as a whole may constitute a Radio Access Network (RAN). The network 90 may be a core network. In this case, the system 10 may constitute a RAN by radio base stations 200 below the core network. In this case, for example, an information processing infrastructure may be connected below the core network, and the radio base stations 200 may be connected below the information processing infrastructure. In this case, the control device 100 may be connected to the information processing infrastructure. The control device 100 may be arranged on the information processing infrastructure.

[0024] The RAN comprising the system 10 may include multiple different frequencies. A user 80 may use a user terminal 82 to receive wireless communication services.

[0025] The control device 100 may control wireless communication services provided by the system 10. For example, the control device 100 controls handover of a user terminal 82. For example, the control device 100 controls cell reselection of the user terminal 82. In the example shown in Fig. 1 , the control device 100 controls, via a network 90 and multiple radio base stations 200, a user terminal 82 residing in a cell 20 formed by multiple radio base stations 200.

[0026] In the above example, there may be multiple information processing infrastructures. The information processing infrastructures may be installed in corresponding regions. The regions may be, for example, regions with an area equivalent to that of each prefecture in Japan. The regions may be, for example, regions with an area smaller than that of each prefecture in Japan. The regions may be, for example, regions with an area larger than that of each prefecture in Japan.

[0027] In the above example, the information processing infrastructure may have multiple layers. For example, the upper information processing infrastructure may be called a management infrastructure, and the lower information processing infrastructure may be called a distributed infrastructure. The management infrastructure may be called a Core Brain, and the distributed infrastructure may be called a Regional Brain. For example, if a two-layer distributed infrastructure is placed below the management infrastructure, the management infrastructure may be called a Core Brain, the distributed infrastructure at the layer below that may be called a Regional Brain, and the distributed infrastructure at the layer below that may be called a Sub-Regional Brain.

[0028] The information processing infrastructure may be equipped with one or more central processing units (CPUs). The information processing infrastructure may be equipped with one or more graphics processing units (GPUs). The information processing infrastructure may be equipped with multiple super chips, each of which has a CPU and a GPU connected via an interconnect. The interconnect may have memory consistency and be capable of achieving high bandwidth and low latency. In this way, the information processing infrastructure may have CPU resources and GPU resources as computational resources.

[0029] 2 is a schematic diagram illustrating an example of control of a wireless communication service by the control device 100. In the example illustrated in FIG. 2, a train 40 carrying a plurality of users 80 carrying user terminals 82 is located at a station 42. The train 40 departs from the station 42, travels along tracks 44, and travels through a section 45 arriving at a station 43.

[0030] In this example, the section 45 is covered by a plurality of cells including cells with different frequencies. In the example shown in Fig. 2, the section 45 is covered by four cells 20 with frequency A, three cells 20 with frequency B, and two cells 20 with frequency C. In the example shown in Fig. 2, the communication traffic of the cell 20 with frequency A that covers the station 43 is congested, and accepting a handover from another cell 20 would further worsen the congestion.

[0031] Fig. 3 is an explanatory diagram for explaining the prior art. Fig. 3 shows a state in which a train 40 has moved from the state shown in Fig. 2, traveled along a track 44, and arrived at a station 43.

[0032] As mentioned above, in conventional mobile communication control, once user terminal 82 is within range of a certain frequency, it tends to continue to use that frequency thereafter. Therefore, user terminal 82 on train 40 tends to continue to use frequency A, which it once was within range of at station 42, even on track 44 and at station 43.

[0033] Therefore, as shown in the example of Fig. 3, if no measures are taken, user terminal 82 on train 40 that was in cell 20 of frequency A in Fig. 2 will hand over to cell 20 of frequency A as train 40 moves along tracks 44, and when train 40 arrives at station 43, it will hand over to cell 20 of frequency A that covers station 43, which is already congested, as shown in Fig. 3. This will further deteriorate communication for the user terminal that was in cell 20 that is already congested, and will also deteriorate communication for user terminal 82 on train 40.

[0034] Next, as one embodiment of the present invention, an embodiment in which the starting state is shown in FIG. 2 and the states transition in the order of FIG. 4, FIG. 5, and FIG. 6 will be described. In FIG. 2, the control device 100 identifies a congested cell where communication traffic is congested from a plurality of cells 20 including cells 20 of different frequencies. For example, from the four cells 20 of frequency A, three cells 20 of frequency B, and two cells 20 of frequency C shown in FIG. 2, the control device 100 identifies the cell 20 of frequency A that covers station 43 as the congested cell.

[0035] The following describes a specific example of how the control device 100 identifies a congested cell. The specific example is merely an example, and the method by which the control device 100 identifies a congested cell may be a method other than the specific example.

[0036] The control device 100 may acquire performance information for each of the multiple cells 20. For example, the control device 100 may acquire information on the number of connected users and / or information on downlink throughput for each of the four cells 20 of frequency A, three cells 20 of frequency B, and two cells 20 of frequency C shown in Fig. 2. The information on the number of connected users may be the number of RRC_CU (Radio Resource Control_Connected Users). The information on downlink throughput may be DL (Downlink) User throughput.

[0037] The control device 100 may identify, as a congested cell, a cell 20 determined to have congested communication traffic based on performance information of a plurality of cells 20. For example, the control device 100 may determine that the cell 20 is congested when the number of connected users of the cell 20 is greater than a predetermined threshold.

[0038] For example, the control device 100 may determine that the cell 20 is congested when the downlink throughput of the cell 20 is smaller than a predetermined threshold. For example, the control device 100 may determine that the cell 20 is congested when the number of connected users of the cell 20 is larger than a predetermined threshold and the downlink throughput is smaller than a predetermined threshold.

[0039] The control device 100 may store a learning model that receives performance information of a plurality of cells 20 as an input and outputs at least one of a cell 20 in which communication traffic is congested and a cell 20 that is predicted to become congested among the plurality of cells 20. The control device 100 may identify a congested cell by inputting the acquired performance information of the plurality of cells 20 into the learning model.

[0040] The control device 100 identifies, from among the multiple cells 20, a cell 20 that has the same frequency as the congested cell and into which multiple user terminals 82 currently located are predicted to move to an area covered by the congested cell, as a source cell. For example, from among the four cells 20 of frequency A, three cells 20 of frequency B, and two cells 20 of frequency C shown in Fig. 2, the control device 100 identifies the cell 20 of frequency A that covers the station 42 as the source cell.

[0041] The following describes a specific example of how the control device 100 identifies a source cell. The specific example is merely an example, and the method by which the control device 100 identifies a source cell may be a method other than the specific example.

[0042] The control device 100 may identify the source cell based on changes in the congestion state of communication traffic over time in the past in a plurality of cells 20. For example, public transportation such as trains and buses have predetermined travel routes, so when a fully loaded public transportation vehicle or the like travels along the travel route, a large number of user terminals 82 will travel together along the travel route.

[0043] In this case, since the congestion state of communication traffic changes in time series along the moving route, multiple adjacent cells 20 using the same frequency become congested in time series order. For example, the control device 100 may identify the moving source cell by using this time series order.

[0044] When a cell 20 covering a station is identified as a congested cell, the control device 100 may identify the cell 20 covering the identified station as the source cell based on the connection relationship with the station covered by the congested cell.

[0045] 2, stations 42 and 43 are adjacent to each other. For example, when the control device 100 identifies the cell 20 of frequency A that covers station 43 as a congested cell, the control device 100 identifies station 42 that is adjacent to and connected to station 43, which is the congested cell, and identifies cell 20 of frequency A that covers station 42 as the source cell.

[0046] Here, the case where the control device 100 identifies one station adjacent to the station covered by the congested cell and identifies the cell 20 covering that station as the source cell has been described as an example, but the present invention is not limited to this. For example, the control device 100 may identify two or more stations adjacent to the congested station and identify the cell 20 covering that station as the source cell. For example, the control device 100 may identify each of a plurality of stations connected to the station covered by the congested cell and identify each of a plurality of cells 20 covering each of the plurality of stations as the source cell.

[0047] 2, the cell 20 that covers the station identified based on the connection relationship with the station covered by the congested cell is identified as the source cell, but the source cell does not have to be the cell 20 that covers the station. For example, the control device 100 identifies the cell 20 that covers the train 40 on the track 44 that is identified based on the connection relationship with the station covered by the congested cell and the distance from the station covered by the congested cell as the source cell.

[0048] For example, the control device 100 identifies, from among multiple trains 40 on a railway line 44 that are connected to a station covered by the congested cell, a cell 20 that covers a train 40 whose distance from the station covered by the congested cell is equal to or less than a predetermined threshold. For example, the control device 100 acquires communication KPIs (Key Performance Indicators) of each of multiple cells 20 that cover a railway line 44 that is connected to a station covered by the congested cell and that exist within a range where the distance from the station covered by the congested cell is equal to or less than the threshold, and identifies the cell 20 whose communication KPI value satisfies a predetermined condition as the source cell.

[0049] For example, in cases where the distance between adjacent stations on express lines such as the Shinkansen or local lines is relatively large, it may be preferable from the perspective of estimating processing load and congestion to identify the source cell when train 40 departs from the adjacent station and approaches a station covered by a congested cell, rather than when train 40 enters cell 20 that covers the adjacent station. The above configuration is expected to be effective in such cases.

[0050] When a cell 20 covering a station is identified as a congested cell, the control device 100 may identify the cell 20 covering the identified station as the source cell based on the connection relationship with the station covered by the congested cell and timetable information. In particular, in countries or regions where it is important for public transportation to operate on schedule and on schedule operation is actually realized, by using timetable information in addition to the connection relationship between stations, it is possible to identify what type of train or the like will arrive at the station covered by the congested cell and at what time, making it possible to more accurately identify the source cell.

[0051] The control device 100 may identify, as a source cell, a cell from which multiple user terminals 82 currently in service are predicted to move to an area covered by a congested cell, based on calendar information including date and time. For example, during certain time periods on weekdays, such as mornings or evenings, many people use public transportation to commute to work or school, and a specific station may be congested. The control device 100 may identify, as a source cell, multiple cells 20 that cover an area near such a congested station, for example, only during certain time periods on weekdays, such as mornings or evenings. The control device 100 may also identify, as a source cell, the cell 20 that covers the congested station itself. This allows, for example, the congested frequencies of the congested station to be vacant in advance during the congested time periods, thereby suppressing congestion.

[0052] The control device 100 controls so that multiple user terminals 82 present in the source cell can easily hand over to a congested cell and a cell 20 using a frequency different from that of the source cell. For example, the control device 100 controls so that a user terminal 82 in a train 40 located at a station 42 in Fig. 2 can easily hand over to a cell using frequency B or frequency C different from frequency A.

[0053] The following describes a specific example of control of handover of the user terminal 82 by the control device 100. The specific example is merely an example, and the control of handover, etc. of the user terminal 82 by the control device 100 may be performed in a manner other than the specific example.

[0054] The control device 100 may perform control to change parameters related to handover of multiple user terminals 82 so as to facilitate handover to a congested cell and a cell using a frequency different from that of the source cell. For example, the control device 100 performs control to change the threshold value of an event trigger for transmitting a measurement report or change the offset value for multiple user terminals 82 located in the source cell.

[0055] The user terminal 82 may issue a measurement report based on a measurement configuration specified in advance by the radio base station 200. If the measurement result satisfies the conditions specified in the measurement configuration, the user terminal 82 may transmit a measurement report to the radio base station 200. The measurement configuration includes information such as information indicating the frequency to be measured, information indicating the cell to be measured, information indicating the beam to be measured, the measurement cycle, and an event trigger threshold for transmitting the measurement report.

[0056] Based on the received measurement report, the radio base station 200 may determine whether or not to hand over the user terminal 82. Specifically, for example, the radio base station 200 determines whether or not handover is necessary based on measurement values ​​such as RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), and SINR (Signal-to-Interference-plus-Noise Ratio) included in the measurement report.

[0057] Therefore, by having the control device 100 control the multiple user terminals 82 located in the source cell to change the threshold value of the event trigger for transmitting measurement reports or change the offset value, the radio base station 200 increases the opportunities to receive measurement reports from the user terminals 82.

[0058] Additionally, the control device 100 may change the threshold value used by the radio base station 200 to determine whether or not to hand over the user terminal 82. Specifically, the control device 100 changes the threshold value of at least one of the radio base station 200 of the source cell and the radio base station 200 of the handover destination cell. This increases the number of opportunities for the radio base station 200 to determine whether or not to hand over the user terminal 82, making it easier for the user terminal 82 to be handed over. Hereinafter, this situation may be referred to as "making handover easier."

[0059] For example, if the event trigger is an A3 trigger, the control device 100 changes the offset values ​​of the serving cell and neighbor cell to decrease them. For example, the control device 100 changes the offset value of the RSRP to decrease them. For example, the control device 100 changes the offset value of the RSRQ to decrease them. This makes it easier for the A3 trigger to be activated, even if the RSRP, etc. of the neighbor cell exceeds the RSRP, etc. of the serving cell by a small amount, making it easier for the user terminal 82 to transmit a measurement report.

[0060] In addition to changing the offset value, the control device 100 may also change the hysteresis value to decrease it, thereby reducing the delay from when the offset value trigger condition is satisfied until the actual handover occurs, making the handover easier.

[0061] For example, if the event trigger is an A5 trigger, the control device 100 increases the threshold value of RSRP from the serving cell. The control device 100 may also decrease the threshold value of RSRP from neighbor cells. The control device 100 may increase the threshold value of RSRP of the serving cell and decrease the threshold value of RSRP of the neighbor cell. This makes it easier for the user terminal 82 to transmit measurement reports.

[0062] The control device 100 may change the threshold value of the RSRQ from the serving cell to a larger value. The control device 100 may change the threshold value of the RSRQ from the neighbor cell to a smaller value. The control device 100 may change the threshold value of the RSRQ of the serving cell to a larger value, and may change the threshold value of the RSRQ of the neighbor cell to a smaller value. This makes it easier for the user terminal 82 to transmit a measurement report.

[0063] In addition to changing the threshold value, the control device 100 may also change the hysteresis value to decrease it, thereby reducing the delay from when the offset value trigger condition is satisfied until the actual handover occurs, making the handover easier.

[0064] The control device 100 may change the levels of RSRP and the like of the multiple cells 20. For example, the control device 100 may change the value of CIO (Cell Individual Offset). For example, the control device 100 may increase the value of CIO of a cell 20 among the multiple cells 20 that has a frequency different from that of a congested cell and a source cell. For example, the control device 100 may decrease the value of CIO of a cell 20 among the multiple cells 20 that has the same frequency as that of a congested cell and a source cell. This makes it easier for the user terminal 82 to transmit a measurement report.

[0065] For example, if the event trigger is an A1 trigger, the control device 100 changes the threshold value of the A1 trigger to a smaller value. For example, the control device 100 changes the threshold value of RSRP to a smaller value. For example, the control device 100 changes the threshold value of RSRQ to a smaller value. This makes it easier for the RSRP etc. from the serving cell to exceed the threshold value, making it easier for the user terminal 82 to transmit a measurement report.

[0066] For example, if the event trigger is an A2 trigger, the control device 100 changes the threshold value of the A2 trigger to a larger value. For example, the control device 100 changes the threshold value of RSRP to a larger value. For example, the control device 100 changes the threshold value of RSRQ to a larger value. This makes it easier for the RSRP etc. from the serving cell to fall below the threshold, making it easier for the user terminal 82 to transmit a measurement report.

[0067] For example, if the event trigger is an A4 trigger, the control device 100 changes the threshold value of the A4 trigger to a smaller value. For example, the control device 100 changes the threshold value of RSRP to a smaller value. For example, the control device 100 changes the threshold value of RSRQ to a smaller value. This makes it easier for RSRP and the like from neighbor cells to exceed the threshold value, making it easier for the user terminal 82 to transmit a measurement report.

[0068] By the control device 100 changing the parameters related to handover as described above for the user terminal 82, the user terminal 82 is more likely to transmit a measurement report to the radio base station 200 when the location of the user terminal 82 is further away from neighbor cells that use the same frequency as the serving cell of the user terminal 82, compared to when nothing is done.

[0069] Since cells 20 using the same frequency are arranged so that their coverage areas do not overlap as much as possible, when a user terminal 82 is located in such a position, the radio wave reception strength from neighbor cells using the same frequency may be weaker. Therefore, the radio wave reception strength from neighbor cells using different frequencies may be relatively stronger. This makes it easier for the user terminal 82 to hand over to a cell using a different frequency from the congested cell and the source cell.

[0070] The control device 100 may control the plurality of user terminals 82 to change the event triggers so as to facilitate handover to a cell using a different frequency from the congested cell and the source cell. For example, if the event trigger is "detection of a cell 20 other than the serving cell that has higher radio wave reception strength than the serving cell at the same frequency as the serving cell," the control device 100 may remove the condition "at the same frequency as the serving cell" and change the event trigger to "detection of a cell 20 other than the serving cell that has higher radio wave reception strength than the serving cell." The control device 100 may change the condition "at the same frequency as the serving cell" and change the event trigger to "at a frequency different from the serving cell" and "detection of a cell 20 other than the serving cell that has higher radio wave reception strength than the serving cell."

[0071] The control device 100 may instruct a plurality of user terminals 82 on the cell 20 to which the user terminals 82 should make handover to a cell using a different frequency from the congested cell and the source cell, so that handover to the cell becomes easier.

[0072] In the area covered by the source cell, there may be user terminals 82 that are idle and not located in the source cell. If such a user terminal 82 selects a cell using the same frequency as the congested cell and the source cell during cell reselection and subsequently becomes located there, the cell 20 using the same frequency may be selected in the subsequent handover, which may worsen the congestion in the congested cell.

[0073] The control device 100 may control the radio base station 200 that generates the source cell to notify an idle user terminal 82 located in an area covered by the source cell of cell reselection parameters that prioritize a cell using a different frequency from that of the source cell. This makes it possible to suppress worsening of congestion caused by the idle user terminal 82 subsequently being present in a congested cell and a cell using the same frequency as the source cell.

[0074] The following describes a specific example of control of cell reselection of the user terminal 82 by the control device 100. The specific example is merely an example, and the control of cell reselection of the user terminal 82 by the control device 100 may be a method other than the specific example.

[0075] For example, the control device 100 may control the radio base station 200 to change the value of the threshold for reselecting a cell 200 that uses the same frequency as the cell in which the user terminal 82 was located immediately before entering the idle state. For example, the control device 100 controls the radio base station 200 to issue a notification to decrease the value of sIntraSearchP. This makes it more difficult for the value of sIntraSearchP to fall below the threshold, making it more difficult for the user terminal 82 to start searching for a cell 20 that uses the same frequency.

[0076] For example, the control device 100 may control the radio base station 200 to change the value of the threshold for reselecting a cell 200 using a different frequency from the cell in which the user terminal 82 was located immediately before entering the idle state. For example, the control device 100 controls the radio base station 200 to issue a notification to increase the value of sNonIntraSearchP. This makes it easier for the value of sNonIntraSearchP to fall below the threshold, making it easier for the user terminal 82 to start searching for a cell 20 using a different frequency.

[0077] For example, the control device 100 may control the radio base station 200 to change a parameter indicating the priority of cell reselection. For example, the control device 100 may control the radio base station 200 to issue a notification to preferentially reselect a congested cell and a cell using a frequency different from that of the source cell. For example, the control device 100 may control the radio base station 200 to issue a notification to lower the priority of reselecting a congested cell and a cell using the same frequency as the source cell.

[0078] For example, the control device 100 may change the value of hysteresis to be smaller. For example, the control device 100 may change the value of qHyst to be smaller.

[0079] 2, the user terminals 82 in the train 40 are controlled by the control device 100 to easily hand over to frequency B or frequency C. Therefore, when the train 40 departs from the station 42 and transitions to the state shown in FIG. 4, some or all of the user terminals 82 in the train 40 that are in the cell of frequency A hand over to the cell 20 of frequency B or frequency C, rather than frequency A. In the example shown in FIG. 4, some of the user terminals 82 in the train 40 that are in the cell of frequency A hand over to the cell of frequency B.

[0080] Next, when the train 40 moves further from the state in Figure 4 and transitions to the state in Figure 5, some or all of the user terminals 82 in the train 40 that are in the cell of frequency A are handed over to a cell of frequency B or frequency C, rather than frequency A. In the example shown in Figure 4, some of the user terminals 82 in the train 40 that are in the cell of frequency A are handed over to a cell of frequency C.

[0081] Next, when the train 40 travels further from the state in Figure 5 and arrives at station 43, transitioning to the state in Figure 6, some or all of the user terminals 82 in the train 40 that are in the cell of frequency A will hand over to the cell 20 of frequency B or frequency C, rather than frequency A. In the example shown in Figure 6, some of the user terminals 82 in the train 40 that are in the cell of frequency A will hand over to the cell of frequency C. In this case, in the state in Figure 2 where the train 40 was located at station 42, many of the user terminals 82 in the train 40 that were in the cell of frequency A will hand over to a cell other than frequency A by the time the state in Figure 6 where the train 40 has arrived at station 43 is reached, it is possible to prevent the congestion in the congested cell from worsening.

[0082] Fig. 7 shows an example of a starting state according to an embodiment of the present invention. In the embodiment described above in which the starting state is shown in Fig. 2 and the states transition in the order of Fig. 4, Fig. 5, and Fig. 6, the starting state may be the state shown in Fig. 7 instead of the state shown in Fig. 2.

[0083] In Fig. 7, differences from Fig. 2 will be mainly described. In the example shown in Fig. 7, not only the cell 20 of frequency A that covers station 43, which is a congested cell, but also the cell 20 of frequency A that covers station 42, which is a source cell, is congested. In this way, it is possible that the source cell is congested. Even in such a case, by performing control similar to the embodiment in which the start state shown in Fig. 2 is set and the states transition in the order of Figs. 4, 5, and 6, it is possible to suppress worsening of congestion in the congested cell.

[0084] Fig. 8 schematically illustrates an example of control of wireless communication services by the control device 100. In the example illustrated in Fig. 8, differences from the example illustrated in Fig. 2 will be mainly described. In the example illustrated in Fig. 8, multiple trains, namely, train 40 and train 41, move through section 45. In the state illustrated in Fig. 8, there is currently no congested cell 20. However, it is expected that in the near future, user terminal 82 in train 40 and user terminal 82 in train 41 will hand over to a cell of frequency A that covers station 43, causing congestion in cell 20 of frequency A that covers station 43.

[0085] Fig. 9 is an explanatory diagram for explaining the conventional technology. Fig. 9 shows a state in which trains 40 and 41 have moved from the state shown in Fig. 8 and arrived at station 43 via tracks 44.

[0086] As described above, in conventional mobile communication control, once user terminal 82 is within the range of a certain frequency, it tends to continue to use that frequency thereafter. Therefore, user terminal 82 on train 40 and train 41 tends to continue to use frequency A, which it has once been within the range of, even on track 44 and at station 43.

[0087] Therefore, as in the example shown in Figure 9, if no measures are taken, user terminal 82 in train 40 and user terminal 82 in train 41, which were each located in cell 20 of frequency A in Figure 8, will hand over to cell 20 of frequency A as train 40 and train 41 move along tracks 44, and when they arrive at station 43, they will hand over to cell 20 of frequency A that covers station 43, as shown in Figure 9, causing congestion.

[0088] Next, as one embodiment of the present invention, an embodiment in which the starting state is shown in FIG. 8 and the state transitions in the order of FIG. 10, FIG. 11, and FIG.

[0089] 8, the control device 100 may identify a congested cell where communication traffic is congested from a plurality of cells including cells of different frequencies. For example, from the four cells 20 of frequency A, three cells 20 of frequency B, and two cells 20 of frequency C shown in FIG. 8, the control device 100 identifies the cell 20 of frequency A that covers station 43 as a congested cell, as a cell 20 where congestion is expected in the near future.

[0090] The control device 100 may identify a cell 20 where it is determined that communication traffic will be congested based on performance information of a plurality of cells 20 as a congested cell. For example, the control device 100 may determine that a cell 20 will be congested in the future by performing arithmetic processing on the performance information of the plurality of cells 20. For example, in the example shown in FIG. 8 , the control device 100 may add up the number of connected users in each of the plurality of frequency A cells 20 that cover section 45, and determine that station 43 will be congested in the near future. The control device 100 may identify a congested cell by inputting the acquired performance information of the plurality of cells into a learning model.

[0091] The control device 100 may identify, from among the multiple cells, a cell 20 that has the same frequency as the congested cell and from which multiple user terminals currently located are expected to move to an area covered by the congested cell, as the source cell. For example, from the four cells 20 of frequency A, three cells 20 of frequency B, and two cells 20 of frequency C shown in Fig. 8, the control device 100 may identify, as the source cell, the cell 20 of frequency A that covers a station 42. The control device 100 may identify, as the source cell, the cell 20 of frequency A that covers an area where a train 41 on a railway line 44 is located.

[0092] The control device 100 may identify multiple source cells. For example, the control device 100 identifies the cell 20 of frequency A that covers the station 42 and the cell 20 of frequency A that covers the area where the train 41 on the track 44 is located as source cells.

[0093] Here, a case will be described in which the control device 100 identifies the cell 20 of frequency A that covers the station 42 as the source cell. The control device 100 may perform control so that multiple user terminals 82 present in the source cell can easily hand over to a cell using a frequency different from that of the congested cell and the source cell. For example, the control device 100 performs control so that the user terminal 82 in the train 40 located at the station 42 in FIG. 8 can easily hand over to a cell using a frequency B or frequency C that is different from that of frequency A. The control device 100 may perform control to change parameters related to handover of multiple user terminals so as to easily hand over to a cell using a frequency different from that of the congested cell and the source cell, similar to the embodiment in which the start state of FIG. 2 is followed by state transitions in the order of FIGS. 4, 5, and 6.

[0094] In the example shown in Fig. 8, the user terminals 82 in the train 40 are controlled by the control device 100 to facilitate handover to frequency B or frequency C. Therefore, when the train 40 departs from the station 42 and transitions to the state shown in Fig. 10, some or all of the user terminals 82 in the train 40 that are in the cell of frequency A hand over to the cell 20 of frequency B or frequency C, rather than frequency A. In the example shown in Fig. 10, some of the user terminals 82 in the train 40 that are in the cell of frequency A hand over to the cell of frequency B.

[0095] Next, when the train 40 moves further from the state in Figure 10 and transitions to the state in Figure 11, some or all of the user terminals 82 in the train 40 that are in the cell of frequency A are handed over to a cell of frequency B or frequency C, rather than frequency A. In the example shown in Figure 11, some of the user terminals 82 in the train 40 that are in the cell of frequency A are handed over to a cell of frequency C.

[0096] Next, when the train 40 travels further from the state in Figure 11 and arrives at station 43, transitioning to the state in Figure 12, some or all of the user terminals 82 in the train 40 that are in the service area of ​​the cell of frequency A are handed over to the cell 20 of frequency B or frequency C, rather than frequency A. In the example shown in Figure 12, some of the user terminals 82 in the train 40 that are in the service area of ​​the cell of frequency A are handed over to the cell of frequency C. In this case, in the state in Figure 8 where the train 40 was located at station 42, many of the user terminals 82 in the train 40 that were in the service area of ​​the cell of frequency A are handed over to cells other than frequency A by the time the state in Figure 12 where the train 40 has arrived at station 43 is reached, congestion in the cell of frequency A that covers station 43 can be prevented.

[0097] 8, it will be understood by those skilled in the art that the control device 100 may perform similar control even when the control device 100 identifies the cell 20 of frequency A that covers the area where the train 41 on the railway line 44 is located as the source cell, rather than the cell 20 of frequency A that covers the station 42. It will also be understood by those skilled in the art that this makes it possible to prevent congestion in the cell of frequency A that covers the station 43.

[0098] The control device 100 may identify multiple source cells. The control device 100 may perform control so that a user terminal 82 residing in a more congested source cell among the identified multiple source cells is preferentially handed over to a cell using a frequency different from that of the congested cell and the source cell. For example, the control device 100 acquires performance information of the multiple source cells and determines, based on the acquired performance information, which source cell the user terminal 82 residing in should be preferentially controlled. For example, the control device 100 determines that control should be preferentially performed on a source cell whose performance value included in the performance information is equal to or greater than a predetermined threshold. The control device 100 may perform control so that a handover to a congested cell and a cell using a frequency different from that of the source cell is more likely for all of the identified multiple source cells.

[0099] 8, even if the control device 100 identifies multiple source cells and identifies the cell 20 of frequency A that covers station 42 and the cell 20 of frequency A that covers the area where train 41 on track 44 is located as the source cells, it will be understood by those skilled in the art that the control device 100 may perform similar control on each of the multiple source cells. By the control device 100 identifying multiple source cells and performing control on user terminals 82 that are located in the multiple source cells, congestion in the cell of frequency A that covers station 43 can be further suppressed.

[0100] Fig. 13 schematically illustrates an example of control of wireless communication services by the control device 100. In the example illustrated in Fig. 13, a plurality of vehicles carrying users 80 carrying user terminals 82 travel along a road 54. In the example illustrated in Fig. 13, the plurality of vehicles travel along a section 55 on the road 54 and arrive at a transportation service facility 53.

[0101] In this example, section 55 is covered by multiple cells including cells with different frequencies. In the example shown in Fig. 13, section 55 is covered by four cells 20 with frequency A, three cells 20 with frequency B, and two cells 20 with frequency C. In the example shown in Fig. 13, communication traffic in cell 20 with frequency A that covers transportation service facility 53 is congested, and accepting a handover from another cell 20 would further worsen the congestion.

[0102] In this example, the road 54 may be a relatively large road. For example, the road 54 may be a trunk road. For example, the road 54 may be a national expressway (highway). In this case, the transportation service facility 53 may be, for example, a service area, a parking area, etc.

[0103] For example, the road 54 may be a general national highway. For example, the road 54 may be a prefectural road. In this case, the transportation service facility 53 may be, for example, a roadside station or the like.

[0104] This example illustrates a state in which communication traffic in cell 20 of frequency A that covers transportation service facility 53 is currently congested, but this is not limiting. For example, the same can be considered when it is predicted that in the near future, multiple vehicles will move to transportation service facility 53 and multiple user terminals 82 in the multiple vehicles will hand over to cell 20 of frequency A that covers transportation service facility 53, causing congestion in cell 20 of frequency A that covers transportation service facility 53.

[0105] In this example, a state in which communication traffic in cell 20 of frequency A that covers transportation service facility 53 is congested is illustrated, but the congested cell 20 does not necessarily have to cover transportation service facility 53. For example, the congested cell 20 may be a cell 20 that covers an area where an event venue is located. For example, in the example shown in FIG. 13 , instead of transportation service facility 53, the event venue may be located at the location of transportation service facility 53.

[0106] In this example, a state in which communication traffic in cell 20 of frequency A that covers transportation service facility 53 is congested is illustrated, but the congested cell 20 does not necessarily have to cover a specific facility, etc. For example, the congested cell 20 may be a cell 20 that covers an area where traffic congestion is occurring. For example, in the example shown in FIG. 13 , instead of transportation service facility 53, an area where congestion is occurring due to multiple vehicles may be located at the location of transportation service facility 53.

[0107] In this example, the multiple vehicles may be automobiles. The size, classification, etc. of the multiple vehicles are not particularly limited. For example, the multiple vehicles may be commercial vehicles such as passenger cars, trucks, and buses. In the example shown in FIG. 13, vehicle 50 is a bus, and vehicles 51 and 52 are passenger cars. For simplicity, the examples shown in FIGS. 13 to 17 will be described using the movements of vehicles 50, 51, and 52, among the multiple vehicles, as examples.

[0108] Fig. 14 is an explanatory diagram for explaining the conventional technology. Fig. 14 shows a state in which vehicles 50, 51, and 52 have each moved from the state shown in Fig. 13, traveled along road 54, and arrived at transportation service facility 53.

[0109] As described above, in conventional mobile communication control, once a user terminal 82 is within the range of a certain frequency, it tends to continue to use that frequency thereafter. Therefore, multiple user terminals 82 in multiple vehicles tend to continue to use frequency A, which they have once been within the range of, on roads 54 and transportation service facilities 53.

[0110] Therefore, as in the example shown in Figure 14, if no measures are taken, user terminal 82 in vehicle 50, user terminal 82 in vehicle 51, and user terminal 82 in vehicle 52, which were each located in cell 20 of frequency A in Figure 13, will hand over to cell 20 of frequency A as vehicle 50, vehicle 51, and vehicle 52 travel along road 54, and when they arrive at transportation service facility 53, they will hand over to cell 20 of frequency A that covers transportation service facility 53, as shown in Figure 14. This will further deteriorate communication for the user terminals located in cell 20 that is already congested, and will also deteriorate communication for user terminals 82 in vehicle 50, vehicle 51, and vehicle 52.

[0111] Next, as one embodiment of the present invention, an embodiment in which the starting state is shown in FIG. 13 and the state transitions in the order of FIG. 15, FIG. 16, and FIG. 17 will be described.

[0112] 13, the control device 100 may identify a congested cell where communication traffic is congested from a plurality of cells including cells of different frequencies. For example, from the four cells 20 of frequency A, three cells 20 of frequency B, and two cells 20 of frequency C shown in FIG. 13, the control device 100 identifies the cell 20 of frequency A that covers the transportation service facility 53 as the congested cell, as the currently congested cell 20. As described above, the control device 100 may identify the cell 20 of frequency A that covers the transportation service facility 53 as the congested cell, as the cell 20 that is expected to become congested in the near future.

[0113] The control device 100 may identify a cell 20 where it is determined that communication traffic will be congested based on performance information of a plurality of cells 20 as a congested cell, similarly to the cases shown in FIGS.

[0114] The control device 100 may identify, from the multiple cells, a cell 20 that has the same frequency as the congested cell and that is expected to be a cell from which multiple user terminals 82 currently located are to move to an area covered by the congested cell, as a source cell. For example, from the four cells 20 of frequency A, three cells 20 of frequency B, and two cells 20 of frequency C shown in Fig. 13, the control device 100 identifies at least one of the cell 20 of frequency A that covers the area in which vehicle 50 is traveling, the cell 20 of frequency A that covers the area in which vehicle 51 is traveling, and the cell 20 of frequency A that covers the area in which vehicle 52 is traveling, as a source cell.

[0115] The control device 100 may specify, as the source cell, a cell that covers an area specified based on the connection relationship of arterial roads to the area covered by the congested cell. For example, in Fig. 13, the road 54 is connected to the transportation service facility 53, so the control device 100 may specify, based on this connection relationship, at least one of the three cells 20 of frequency A that cover the road 54 as the source cell.

[0116] Here, a case will be described in which the control device 100 identifies all three cells 20 of frequency A that cover the road 54 as source cells.

[0117] The control device 100 may perform control so that multiple user terminals 82 located in the source cell can easily hand over to a congested cell and a cell using a frequency different from that of the source cell. For example, the control device 100 performs control so that user terminals 82 in vehicles 50, 51, and 52 located in three cells 20 using frequency A that cover a road 54 in Fig. 13 can easily hand over to a cell using frequency B or frequency C that is different from frequency A. The control device 100 may perform control to change parameters related to handover of multiple user terminals so that handover to a cell using a frequency different from that of the congested cell and the source cell can easily be performed, similar to the embodiment in which the start state of Fig. 2 is followed by state transitions in the order of Figs. 4, 5, and 6.

[0118] 13, the user terminals 82 in the vehicles 50, 51, and 52 are controlled by the control device 100 to facilitate handover to frequency B or frequency C. Therefore, when the vehicles 50, 51, and 52 move along the road 54 and transition to the state shown in FIG. 15, some or all of the user terminals 82 in the vehicles 50, 51, and 52 that are present in the cell of frequency A will hand over to the cell 20 of frequency B or frequency C, rather than frequency A.

[0119] 15 , some of the user terminals 82 in vehicle 50 that are within the coverage area of ​​cell 20 of frequency A hand over to cell 20 of frequency C, some of the user terminals 82 in vehicle 51 hand over to cell 20 of frequency B, and all of the user terminals 82 in vehicle 52 hand over to cell 20 of frequency C. Vehicle 52 arrives at transportation service facility 53, but since user terminal 82 in vehicle 52 has handed over to cell 20 of frequency C, worsening of congestion in cell 20 of frequency A that covers transportation service facility 53 is suppressed, and deterioration of communication for user terminal 82 in vehicle 52 is also suppressed.

[0120] Next, when vehicle 50 and vehicle 51 move further along road 54 from the state in Figure 15 and transition to the state in Figure 16, some or all of the user terminals 82 in vehicle 50 and vehicle 51 that are in the service area of ​​the cell of frequency A are handed over to the cell of frequency B or frequency C, rather than frequency A. In the example shown in Figure 16, some of the user terminals 82 in vehicle 50 that are in the service area of ​​the cell of frequency A are handed over to the cell of frequency B, and some of the user terminals 82 in vehicle 51 are handed over to the cell 20 of frequency B. Vehicle 51 arrives at transportation service facility 53, but user terminal 82 in vehicle 51 has handed over to cell 20 of frequency B, so that worsening congestion in cell 20 of frequency A that covers transportation service facility 53 is suppressed, and deterioration of communication for user terminal 82 in vehicle 51 is suppressed.

[0121] Next, when vehicle 50 travels further from the state in Figure 16 and arrives at transportation service facility 53, transitioning to the state in Figure 17, some or all of user terminals 82 in vehicle 50 that are within the range of the cell of frequency A are handed over to cell 20 of frequency B or frequency C, rather than frequency A. In the example shown in Figure 17, some of the user terminals 82 in vehicle 50 that are within the range of the cell of frequency A are handed over to cell 20 of frequency B. In this case, many of the user terminals 82 in vehicles 50, 51, and 52 that were within the range of the cell of frequency A in the state in Figure 13 are handed over to cells other than frequency A by the time the state in Figure 17 is reached where vehicle 50, vehicle 51, and vehicle 52 have arrived at transportation service facility 53, thereby preventing congestion in the cell of frequency A that covers transportation service facility 53 from worsening.

[0122] Fig. 18 schematically illustrates an example of control of wireless communication services by the control device 100. In the example illustrated in Fig. 18, a plurality of users 80 carrying user terminals 82 are located at an event venue 30. Upon completion of the event, the plurality of users 80 depart from the event venue 30, travel along road 46, and travel along section 47 to arrive at station 43, which is the nearest station.

[0123] In this example, the section 47 is covered by a plurality of cells including cells of different frequencies. In the example shown in Fig. 13, the section 47 is covered by four cells 20 of frequency A, three cells 20 of frequency B, and two cells 20 of frequency C.

[0124] 18, communication traffic is congested in cell 20 of frequency A that covers event venue 30. When multiple users 80 move on section 47 as the event ends, it is expected that the multiple frequency A cells that cover section 47 will become congested in sequence as multiple users 80 move, from cell 20 of frequency A that covers event venue 30 to cell 20 of frequency A that covers station 43.

[0125] 19, 20, and 21 are explanatory diagrams for explaining the prior art. Figures 19, 20, and 21 show the process from the state shown in Figure 18, in which multiple users 80 carrying user terminals 82 move on section 47 and arrive at station 43.

[0126] As mentioned above, in conventional mobile communication control, once a user terminal 82 is within range of a certain frequency, it tends to continue to use that frequency thereafter. Therefore, multiple user terminals 82 tend to continue to use frequency A, which they once were within range of at event venue 30, even on road 46 and at station 43.

[0127] 19 to 21, if no measures are taken, the multiple user terminals 82 at the event venue 30 that were in the frequency A cell 20 in FIG. 18 will hand over to the frequency A cell 20 as the users 80 move along section 47, and the multiple frequency A cells covering section 47 will become congested in order, from the frequency A cell 20 covering the event venue 30 to the frequency A cell 20 covering the station 43. In this case, the multiple user terminals 82 carried by the multiple users 80 will be constantly in a state of communication traffic congestion while the users 80 are moving along section 47, and the satisfaction of the users 80 with the communication service will decrease.

[0128] Next, as one embodiment of the present invention, an embodiment in which the state transitions in the order of FIGS. 22, 23, and 24 starting from the start state shown in FIG. 18 will be described. In FIG. 18, the control device 100 identifies a congested cell where communication traffic is congested from a plurality of cells including cells of different frequencies. For example, from the four cells 20 of frequency A, three cells 20 of frequency B, and two cells 20 of frequency C shown in FIG. 18, the control device 100 identifies the two cells 20 of frequency A covering road 46 and the cell 20 of frequency A covering station 43 as congested cells, as congestion is expected due to the movement of multiple users 80.

[0129] The specific method by which the control device 100 identifies a congested cell is the same as that of the embodiment in which the start state is the above-described FIG. 2 and the state transitions in the order of FIG. 4, FIG. 5, and FIG.

[0130] The control device 100 identifies, as a source cell, a cell 20 having the same frequency as the congested cell from among the multiple cells 20, from which multiple user terminals currently located are predicted to move to an area covered by the congested cell. For example, the control device 100 identifies, as the source cell, the cell 20 having frequency A that covers the event venue 30 from among the four cells 20 having frequency A, three cells 20 having frequency B, and two cells 20 having frequency C shown in Fig. 18.

[0131] The control device 100 may identify, as a source cell, a cell 20 from which a plurality of user terminals 82 currently located are predicted to move to an area covered by the congested cell, based on calendar information including the date and time and information about events held in the surrounding area of ​​the area covered by the congested cell. For example, based on the date and time of the day and the event information, the control device 100 predicts that congestion will occur on the route from the event venue to the nearest station after the event ends on the day the event is held, and therefore identifies, as a source cell, a cell 20 on that route.

[0132] The specific method by which the control device 100 identifies the source cell is the same as that of the embodiment in which the start state is shown in FIG. 2 and the states change in the order of FIG. 4, FIG. 5, and FIG.

[0133] The control device 100 controls so that multiple user terminals 82 present in the source cell can easily hand over to a congested cell and a cell using a frequency different from that of the source cell. For example, the control device 100 controls so that a user terminal 82 located in the event venue 30 in Fig. 18 can easily hand over to a cell using frequency B or frequency C different from frequency A.

[0134] The specific method of handover control of the user terminal 82 by the control device 100 is the same as the embodiment in which the start state is shown in FIG. 2 and the states transition in the order of FIG. 4, FIG. 5, and FIG.

[0135] 18, the user terminal 82 in the event venue 30 is controlled by the control device 100 to easily hand over to frequency B or frequency C. Therefore, when a user 80 carrying the user terminal 82 leaves the event venue 30 and transitions to the state shown in FIG. 22, some or all of the user terminal 82 of the user 80, which is present in the cell of frequency A and moving on section 47, is handed over to the cell 20 of frequency B or frequency C, not frequency A. In the example shown in FIG. 22, some of the user terminals 82 present in the cell of frequency A are handed over to the cell of frequency B. This makes it possible to suppress congestion in the cell 20 of frequency A that covers the road 46.

[0136] Next, when a user 80 carrying a user terminal 82 progresses further from the state in Figure 22 and transitions to the state in Figure 23, some or all of the multiple user terminals 82 present in the cell of frequency A are handed over to a cell of frequency B or frequency C, rather than frequency A. In the example shown in Figure 23, some of the user terminals 82 present in the cell of frequency A are handed over to a cell of frequency C. This makes it possible to suppress congestion in the cell 20 of frequency A that covers the road 46.

[0137] Next, when user 80 carrying user terminal 82 travels further from the state in Figure 23 and arrives at station 43, transitioning to the state in Figure 24, some or all of the user terminals 82 present in the cell of frequency A are handed over to cell 20 of frequency B or frequency C, rather than frequency A. In the example shown in Figure 24, some of the user terminals 82 present in the cell of frequency A are handed over to cell 20 of frequency C. This makes it possible to suppress congestion in cell 20 of frequency A that covers station 43.

[0138] Fig. 25 schematically illustrates an example of control of wireless communication services by the control device 100. In Fig. 25, differences from the example illustrated in Fig. 2 will be mainly described. In the example illustrated in Fig. 25, a section 45 is covered by a cell group 28.

[0139] The cell group 28 may include one or more cells 20 located between the congested cell and the source cell. As in the example shown in Fig. 2, in the example shown in Fig. 20, the control device 100 identifies the cell 20 of frequency A that covers station 43 as the congested cell, and identifies the cell 20 of frequency A that covers station 42 as the source cell.

[0140] In the example shown in Fig. 25, the cell group 28 includes four cells 20 of frequency A, three cells 20 of frequency B, and two cells 20 of frequency C. In the example shown in Fig. 25, of the multiple cells 20 included in the cell group 28, the two cells 20 of frequency C are already in a congested state.

[0141] The control device 100 may change parameters related to handover of multiple user terminals 82 residing in the source cell, depending on the status of the cell group 28. In the example shown in Fig. 25, the control device 100 controls parameters related to handover so that, among the multiple cells 20 included in the cell group 28, the multiple user terminals 82 can easily handover to the cell 20 of frequency B, avoiding two cells 20 of frequency C that are already in a congested state.

[0142] 25, user terminals 82 inside train 40 are controlled by control device 100 to facilitate handover to frequency B. Therefore, as train 40 departs from station 42 and moves along tracks 44 toward station 43, some or all of user terminals 82 inside train 40 that are within the coverage area of ​​frequency A will hand over to the cell of frequency B.

[0143] 25 where train 40 is located at station 42, many of the user terminals 82 on train 40 that were in the cell of frequency A will hand over to cell 20 of frequency B rather than cell 20 of frequency C by the time train 40 reaches the state of FIG. 26 where train 40 has arrived at station 43. Therefore, it is possible to prevent congestion in cell 20 of frequency C from worsening while also preventing congestion in cell 20 of frequency A, which is a congested cell, from worsening further.

[0144] Fig. 27 schematically illustrates an example of control of wireless communication services by the control device 100. In Fig. 27, differences from the example illustrated in Fig. 25 will be mainly described. In the example illustrated in Fig. 27, among the multiple cells 20 included in the cell group 28, the cell 20 of frequency B and the cell 20 of frequency C that cover the station 43 are in a high-load state. The high-load state refers to a state in which the number of connected users is relatively large and user throughput is relatively low, and although congestion has not yet occurred, there is a high possibility of congestion occurring if the number of user terminals 82 and the like within the area increases further.

[0145] Fig. 28 schematically shows an example of control of wireless communication services by the control device 100. Fig. 28 shows a state in which a train 40 has moved from the state shown in Fig. 27, traveled along a track 44, and arrived at a station 43.

[0146] If the control device 100 simply changes the parameters related to the handover of multiple user terminals 82 so as to facilitate handover to a cell 20 having a frequency different from the congested cell and the source cell, it is possible that the handover destinations of multiple user terminals 82 will be biased toward frequency B, as in the example shown in Figure 28, and the cell 20 of frequency B that covers the station 43 will become congested.

[0147] The control device 100 may change parameters related to handover of multiple user terminals 82 located in the source cell, depending on the status of the cell group 28. In the example shown in Fig. 27, the control device 100 controls parameters related to handover so that multiple user terminals 82 can easily hand over to both the cell 20 of frequency B and the cell 20 of frequency C, which cover a station 43 that is already in a high load state, among the multiple cells 20 included in the cell group 28.

[0148] The control device 100 may determine a frequency that makes it easier to hand over multiple user terminals 82 located in the source cell, depending on the status of the cell group 28. In the example shown in Fig. 27, the control device 100 may determine that the frequencies that make it easier to hand over multiple user terminals 82 are both frequency B and frequency C, in response to the fact that, of the multiple cells 20 included in the cell group 28, both the cell 20 of frequency B and the cell 20 of frequency C that cover the station 43 are already in a high load state.

[0149] In this case, the control device 100 may perform control to change parameters related to handover of the multiple user terminals 82 so that the multiple user terminals 82 can easily hand over to the cell using the determined frequency. The control device 100 may determine the amount of change in parameters related to handover of the multiple user terminals 82 located in the source cell, depending on the status of the cell group 28.

[0150] For example, the control device 100 changes parameters related to handover of multiple user terminals 82 so that multiple user terminals 82 located in the source cell can easily be handed over to a congested cell and cells 20 using multiple frequencies different from the frequency of the source cell. For example, the control device 100 changes parameters related to handover of multiple user terminals 82 in multiple stages. For example, the control device 100 changes parameters related to handover of multiple user terminals 82 to different values ​​for each of the multiple stages.

[0151] For example, the control device 100 first changes the parameters related to handover of the multiple user terminals 82 so that the parameters are intermediate values ​​that make it easy for only some of the multiple user terminals 82 to hand over and for the remaining some to continue to be present at the same frequency as the source cell. The control device 100 then changes the parameters related to handover of the multiple user terminals 82 so that the parameters are values ​​that make it easy for the remaining some of the multiple user terminals 82 to hand over.

[0152] 27 , the control device 100 first changes the parameters related to handover of the plurality of user terminals 82 to a first value that allows some of the user terminals 82 to be handed over to the cell 20 of frequency B, among the plurality of user terminals 82 present in the source cell. Thereafter, the train 40 travels through section 45, causing these some of the user terminals 82 to hand over to the cell 20 of frequency B. The control device 100 then changes the parameters related to handover of the plurality of user terminals 82 to a second value that allows the remaining some of the user terminals 82 to hand over. Thereafter, the train 40 travels through section 45, causing these remaining some of the user terminals 82 to hand over to the cell 20 of frequency C.

[0153] This makes it possible to control the distribution of multiple user terminals 82 that were located in the source cell to the congested cell and multiple cells 20 that use frequencies different from the frequency of the source cell, making handover easier. Note that the first and second values ​​of the handover-related parameters do not necessarily have to be different values, and may be the same value.

[0154] For example, when a cell 20 using a frequency different from the frequencies of the congested cell and the source cell accepts handovers of some of the user terminals 82 residing in the source cell, the control device 100 may change the parameters related to handover within a range that is not expected to cause congestion. For example, in the example shown in Fig. 27 , there is a possibility that the cell 20 using frequency B that covers the station 43 will become congested if it accepts handovers of an additional 20 user terminals 82, and there is a possibility that the cell 20 using frequency C that covers the station 43 will become congested if it accepts handovers of 50 user terminals 82. In this case, the control device 100 may determine the amount of change in the parameters related to handover so that the number of user terminals 82 that hand over to the cell 20 using frequency B that covers the station 43 is likely to be less than 20, or may determine the amount of change in the parameters related to handover so that the number of user terminals 82 that hand over to the cell 20 using frequency C that covers the station 43 is likely to be less than 50.

[0155] 27, the user terminals 82 inside the train 40 are controlled by the control device 100 so as to facilitate handover to the cell 20 of frequency B and the cell 20 of frequency C. Therefore, as the train 40 departs from station 42 and moves along the tracks 44 toward station 43, some of the user terminals 82 inside the train 40 that are within the coverage area of ​​the cell of frequency A hand over to the cell 20 of frequency B, and some of the remaining user terminals hand over to the cell 20 of frequency B.

[0156] As a result, in the state of Fig. 27 where train 40 is located at station 42, some of the user terminals 82 inside train 40 that were in the frequency A cell hand over to cell 20 of frequency B during the time it takes for train 40 to arrive at station 43 in the state of Fig. 29 where train 40 has arrived at station 43, and some of the remaining user terminals hand over to cell 20 of frequency C. This makes it possible to prevent cell 20 of frequency B and cell 20 of frequency C that cover station 43, which was in a high load state, from becoming congested, while also preventing further worsening of congestion in the congested cells.

[0157] 30 schematically illustrates an example of the functional configuration of the control device 100. In FIG. 30, the control device 100 includes an information acquisition unit 110, a storage unit 120, a congested cell identification unit 130, a source cell identification unit 140, and a handover control unit 150.

[0158] The information acquisition unit 110 may acquire various types of information. For example, the information acquisition unit 110 acquires information related to the wireless communication services provided by the system 10. For example, the information acquisition unit 110 acquires information related to the geographical location of the wireless base station 200 and information on the cells 20 formed by the wireless base station 200 for each frequency.

[0159] The information acquiring unit 110 may acquire performance information for each of the plurality of cells 20. The information acquiring unit 110 may acquire timetable information. The information acquiring unit 110 may acquire calendar information. The information acquiring unit 110 may acquire information on the congestion state of communication traffic in the past time series of the plurality of cells 20.

[0160] The information acquisition unit 110 may acquire information indicating connections between stations of public transportation. For example, the information acquisition unit 110 may acquire a train route map. For example, the information acquisition unit 110 may acquire a train diagram.

[0161] The storage unit 120 may store various types of information. For example, the storage unit 120 stores various types of information acquired by the information acquisition unit 110. For example, the storage unit 120 may store various learning models used by the control device 100.

[0162] The memory unit 120 may store a learning model that takes performance information of multiple cells 20 as input and outputs at least one of the cells among the multiple cells 20 whose communication traffic is congested and the cells that are predicted to be congested.

[0163] The congested cell identifying unit 130 identifies a congested cell in which communication traffic is congested from a plurality of cells 20 including cells 20 using different frequencies. The congested cell identifying unit 130 may identify a cell 20 in which communication traffic is determined to be congested based on performance information of the plurality of cells 20 as a congested cell.

[0164] The congested cell identifying unit 130 may identify a congested cell by inputting the performance information of the plurality of cells 20 acquired by the information acquiring unit 110 into a learning model stored in the storage unit 120 .

[0165] The source cell identifying unit 140 identifies, from the plurality of cells 20, a cell 20 that uses the same frequency as the congested cell and that is predicted to be used by a plurality of user terminals 82 currently located in the cell 20 to move to an area covered by the congested cell, as a source cell. The source cell identifying unit 140 may identify a plurality of source cells. The source cell identifying unit 140 may identify a source cell based on changes in the congestion state of communication traffic in the plurality of cells 20 over time.

[0166] When a cell 20 covering a station is identified as a congested cell, the source cell identification unit 140 may identify, as the source cell, the cell 20 covering the station identified based on the connection relationship with the station covered by the congested cell.When a cell 20 covering a station is identified as a congested cell, the source cell identification unit 140 may identify, as the source cell, the cell covering the station identified based on the connection relationship with the station covered by the congested cell and timetable information.

[0167] The source cell identification unit 140 may identify, based on calendar information including date and time, a cell 20 from which multiple user terminals 82 currently in the area are expected to move to an area covered by a congested cell, as the source cell.

[0168] The source cell specifying unit 140 may specify, as the source cell, the cell 20 that covers the area specified based on the connection relationship of the arterial roads to the area covered by the congested cell.

[0169] The handover control unit 150 may perform control so that multiple user terminals 82 located in the source cell can easily be handed over to the congested cell and the cell 20 using a frequency different from that of the source cell. The handover control unit 150 may perform control so as to change parameters related to handover of multiple user terminals 82 so that multiple user terminals 82 can easily be handed over to the congested cell and the cell 20 using a frequency different from that of the source cell.

[0170] The handover control unit 150 may perform control so that a user terminal 82 located in a more congested source cell among the identified multiple source cells is given priority so as to facilitate handover to a cell 20 that uses a different frequency from the congested cell and the source cell.

[0171] The handover control unit 150 may perform control to change the event trigger so as to facilitate handover to the cell 20 using a frequency different from that of the congested cell and the source cell. The handover control unit 150 may also instruct the handover destination cell 20 so as to facilitate handover to the cell 20 using a frequency different from that of the congested cell and the source cell.

[0172] The handover control unit 150 may control the radio base station 200 that generates the source cell to notify an idle user terminal 82 located in an area covered by the source cell of cell reselection parameters that prioritize a cell 20 that uses a different frequency from that of the source cell.

[0173] The handover control unit 150 may change parameters related to handover of multiple user terminals 82 located in the source cell, depending on the conditions of the congested cell, the source cell, and the cell group 28.

[0174] The handover control unit 150 may determine a frequency that makes it easier for multiple user terminals 82 located in the source cell to hand over, depending on the status of the cell group 28. The handover control unit 150 may control to change parameters related to handover of the multiple user terminals 82, so that it is easier for the multiple user terminals 82 to hand over to the cell 20 using the determined frequency. The handover control unit 150 may determine the amount of change in parameters related to handover of the multiple user terminals 82 located in the source cell, depending on the status of the cell group 28.

[0175] 31 shows an example of a processing flow by the control device 100. In step (sometimes abbreviated as S) 102, the congested cell identifying unit 130 identifies a congested cell in which communication traffic is congested from among a plurality of cells 20 including cells using different frequencies.

[0176] In S104, the source cell identification unit 140 identifies, from among the multiple cells 20, a cell 20 that has the same frequency as the congested cell and from which multiple user terminals 82 currently located are expected to move to an area covered by the congested cell, as the source cell.

[0177] In S106, the handover control unit 150 performs control so that a plurality of user terminals 82 existing in the source cell can easily be handed over to the congested cell and the cell 20 using a frequency different from that of the source cell.

[0178] 32 schematically illustrates an example of the hardware configuration of a computer 1200 functioning as the control device 100. A program installed on the computer 1200 can cause the computer 1200 to function as one or more "units" of the device according to the present embodiment, or can cause the computer 1200 to perform operations associated with the device according to the present embodiment or one or more "units," and / or can cause the computer 1200 to perform a process according to the present embodiment or steps of the process. Such a program can be executed by the CPU 1212 to cause the computer 1200 to perform specific operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

[0179] The computer 1200 according to this embodiment includes a CPU 1212, a RAM 1214, and a graphics controller 1216, which are interconnected by a host controller 1210. The computer 1200 also includes input / output units such as a communications interface 1222, a storage device 1224, a DVD drive, and an IC card drive, which are connected to the host controller 1210 via an input / output controller 1220. The DVD drive may be a DVD-ROM drive, a DVD-RAM drive, or the like. The storage device 1224 may be a hard disk drive, a solid-state drive, or the like. The computer 1200 also includes a ROM 1230 and legacy input / output units such as a keyboard, which are connected to the input / output controller 1220 via an input / output chip 1240.

[0180] The CPU 1212 operates according to programs stored in the ROM 1230 and the RAM 1214, thereby controlling each unit. The graphics controller 1216 acquires image data generated by the CPU 1212 into a frame buffer or the like provided in the RAM 1214 or into the graphics controller itself, and causes the image data to be displayed on the display device 1218.

[0181] The communication interface 1222 communicates with other electronic devices via a network. The storage device 1224 stores programs and data used by the CPU 1212 in the computer 1200. The DVD drive reads programs or data from a DVD-ROM or the like and provides them to the storage device 1224. The IC card drive reads programs and data from an IC card and / or writes programs and data to an IC card.

[0182] The ROM 1230 stores therein a boot program or the like that is executed by the computer 1200 upon activation, and / or programs that depend on the hardware of the computer 1200. The input / output chip 1240 may also connect various input / output units to the input / output controller 1220 via a USB port, a parallel port, a serial port, a keyboard port, a mouse port, etc.

[0183] The programs are provided by a computer-readable storage medium such as a DVD-ROM or an IC card. The programs are read from the computer-readable storage medium, installed in the storage device 1224, RAM 1214, or ROM 1230, which are also examples of computer-readable storage media, and executed by the CPU 1212. Information processing described in these programs is read by the computer 1200, and causes cooperation between the programs and the various types of hardware resources described above. An apparatus or method may be configured by implementing operations or processing of information in accordance with the use of the computer 1200.

[0184] For example, when communication is performed between the computer 1200 and an external device, the CPU 1212 may execute a communication program loaded into the RAM 1214 and instruct the communication interface 1222 to perform communication processing based on the processing described in the communication program. Under the control of the CPU 1212, the communication interface 1222 reads transmission data stored in a transmission buffer area provided in the RAM 1214, the storage device 1224, a DVD-ROM, or a recording medium such as an IC card, and transmits the read transmission data to the network, or writes reception data received from the network to a reception buffer area or the like provided on the recording medium.

[0185] Furthermore, the CPU 1212 may cause all or a necessary portion of a file or database stored in an external recording medium such as the storage device 1224, a DVD drive (DVD-ROM), an IC card, etc. to be read into the RAM 1214, and may perform various types of processing on the data on the RAM 1214. The CPU 1212 may then write back the processed data to the external recording medium.

[0186] Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and may undergo information processing. The CPU 1212 may perform various types of processing on data read from the RAM 1214, including various types of operations, information processing, conditional judgment, conditional branching, unconditional branching, information search / replacement, etc., as described throughout this disclosure and specified by the instruction sequences of the programs, and write the results back to the RAM 1214. The CPU 1212 may also search for information in a file, database, etc. on the recording medium. For example, if multiple entries, each having an attribute value of a first attribute associated with an attribute value of a second attribute, are stored on the recording medium, the CPU 1212 may search for an entry whose attribute value of the first attribute matches a specified condition from among the multiple entries, read the attribute value of the second attribute stored in the entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition.

[0187] The above-described programs or software modules may be stored in a computer-readable storage medium on or near the computer 1200. A recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can also be used as a computer-readable storage medium, thereby providing the programs to the computer 1200 via the network.

[0188] The blocks in the flowcharts and block diagrams in the present embodiments may represent stages of a process in which an operation is performed or "parts" of an apparatus responsible for performing the operation. Particular stages and "parts" may be implemented by dedicated circuitry, programmable circuitry provided with computer-readable instructions stored on a computer-readable storage medium, and / or a processor provided with computer-readable instructions stored on a computer-readable storage medium. The dedicated circuitry may include digital and / or analog hardware circuits, including integrated circuits (ICs) and / or discrete circuits. The programmable circuitry may include reconfigurable hardware circuits, such as field programmable gate arrays (FPGAs) and programmable logic arrays (PLAs), including AND, OR, XOR, NAND, NOR, and other logical operations, flip-flops, registers, and memory elements.

[0189] A computer-readable storage medium may include any tangible device capable of storing instructions that are executed by an appropriate device, such that a computer-readable storage medium having instructions stored thereon comprises an article of manufacture, including instructions that can be executed to create means for performing the operations specified in the flowcharts or block diagrams. Examples of computer-readable storage media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, etc. More specific examples of computer-readable storage media may include floppy disks, diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), compact disc read-only memory (CD-ROM), digital versatile disc (DVD), Blu-ray disc, memory stick, integrated circuit card, etc.

[0190] The computer readable instructions may include either assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, JAVA®, C++, etc., and conventional procedural programming languages ​​such as the “C” programming language or similar programming languages.

[0191] Computer-readable instructions may be provided to a general-purpose computer, a special-purpose computer, or another programmable data processing device, or a programmable circuit, either locally or via a local area network (LAN) or a wide area network (WAN) such as the Internet, so that the processor of the programmable data processing device, such as a computer, or the programmable circuit executes the computer-readable instructions to generate means for performing the operations specified in the flowcharts or block diagrams. Here, the computer may be a personal computer (PC), a tablet computer, a smartphone, a workstation, a server computer, a general-purpose computer, a special-purpose computer, or the like, or may be a computer system in which multiple computers are connected. Such a computer system in which multiple computers are connected is also called a distributed computing system, and is a broad definition of computers. In a distributed computing system, multiple computers collectively execute a program by each executing a portion of the program and passing data between the computers as needed during program execution.

[0192] Examples of processors include computer processors, central processing units, processing units, microprocessors, digital signal processors, controllers, microcontrollers, etc. A computer may have one or more processors. In a multiprocessor system with multiple processors, each processor executes a portion of a program and passes data between processors as needed during program execution, allowing the multiple processors to collectively execute the program. For example, in multitasking, each of the multiple processors may execute a portion of each task in small chunks by switching tasks at time slice intervals. In this case, which portion of a program each processor executes changes dynamically. Which portion of a program each of the multiple processors executes may also be statically determined by multiprocessor-aware programming.

[0193] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0194] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0195] 10 system, 20 cell, 28 cell group, 30 event venue, 40 train, 41 train, 42 station, 43 station, 44 track, 45 section, 46 road, 47 section, 50 vehicle, 51 vehicle, 52 vehicle, 53 transportation service facility, 54 road, 55 section, 80 user, 82 user terminal, 90 network, 100 control device, 110 information acquisition unit, 120 memory unit, 130 congested cell identification unit, 140 source cell identification unit, 150 handover control unit, 200 radio base station, 1200 computer, 1210 host controller, 1212 CPU, 1214 RAM, 1216 graphics controller, 1218 display device, 1220 input / output controller, 1222 communication interface, 1224 storage device, 1230 ROM, 1240 input / output chip

Claims

1. a congested cell identifying unit that identifies a congested cell where communication traffic is congested from a plurality of cells including cells using different frequencies; a source cell identification unit that identifies, from the plurality of cells, a cell that has the same frequency as the congested cell and to which a plurality of user terminals currently located are predicted to move to an area covered by the congested cell, as a source cell; a handover control unit that performs control so that a plurality of user terminals present in the source cell can easily be handed over to the congested cell and a cell using a frequency different from that of the source cell; A control device comprising:

2. 2. The control device according to claim 1, wherein the handover control unit controls to change parameters related to handover of the plurality of user terminals present in the source cell so that the plurality of user terminals can easily hand over to the congested cell and a cell using a frequency different from that of the source cell.

3. an information acquisition unit that acquires performance information of each of the plurality of cells; Equipped with The control device according to claim 1 , wherein the congested cell identifying unit identifies a cell determined to have congested communication traffic based on the performance information of the plurality of cells as the congested cell.

4. a storage unit that stores a learning model that receives performance information of a plurality of cells as an input and outputs at least one of a cell in which communication traffic is congested and a cell that is predicted to be congested among the plurality of cells; an information acquisition unit that acquires performance information of each of the plurality of cells; Equipped with The control device according to claim 1 , wherein the congested cell identifying unit identifies the congested cell by inputting the performance information of the plurality of cells acquired by the information acquiring unit into the learning model.

5. The control device according to claim 1 , wherein the source cell identifying unit identifies the source cell based on a change in a congestion state of communication traffic in the past in a time series in the plurality of cells.

6. The control device according to claim 1, wherein when a cell covering a station is identified as the congested cell by the congested cell identification unit, the source cell identification unit identifies as the source cell a cell covering the identified station based on a connection relationship with the station covered by the congested cell.

7. The control device according to claim 6, wherein when the congested cell identification unit identifies a cell covering a station as the congested cell, the source cell identification unit identifies a cell covering the station identified based on a connection relationship between the congested cell and the station covered by the congested cell and timetable information as the source cell.

8. The control device according to claim 1 , wherein the source cell specifying unit specifies, as the source cell, a cell covering an area specified based on a connection relationship of arterial roads to the area covered by the congested cell.

9. 2. The control device according to claim 1, wherein the handover control unit controls the radio base station generating the source cell to notify an idle user terminal located in an area covered by the source cell of cell reselection parameters that prioritize a cell using a frequency different from that of the source cell.

10. 10. The control device according to claim 1, wherein the handover control unit changes parameters related to handover of the plurality of user terminals located in the source cell according to a status of a cell group including the congested cell, the source cell, and one or more cells located between the congested cell and the source cell.

11. 11. The control device according to claim 10, wherein the handover control unit determines a frequency that makes it easier to hand over the plurality of user terminals present in the source cell according to a status of the cell group, and controls to change parameters related to handover of the plurality of user terminals so that the plurality of user terminals can easily hand over to a cell using the determined frequency.

12. The control device according to claim 10 , wherein the handover control unit determines an amount of change in a parameter related to handover of the plurality of user terminals located in the source cell, depending on a state of the group of cells.

13. 1. A computer-implemented control method comprising: a congested cell identifying step of identifying a congested cell in which communication traffic is congested from a plurality of cells including cells with different frequencies; a source cell identification step of identifying, from the plurality of cells, a cell that has the same frequency as the congested cell and from which a plurality of user terminals currently located in the congested cell are predicted to move into an area covered by the congested cell, as a source cell; a handover control step of controlling the handover so that a plurality of user terminals present in the source cell can easily hand over to the congested cell and a cell using a frequency different from that of the source cell; A control method comprising:

14. A program for causing a computer to execute the control method according to claim 13.

Images