JP6608636B2 - Information processing method, information processing apparatus, and information processing program - Google Patents

Description

  The present invention relates to a handover in which a mobile terminal switches base stations as it moves.

  FIG. 1 is a conceptual diagram illustrating a configuration of a general wireless communication system.

  The wireless communication system generally includes a mobile terminal 10, a base station 30, a mobile communication core network 50, and a network management system 90, as shown in FIG.

  The base station 30 is provided with a cell 35 in a range where the radio link 20 with the mobile terminal 10 is effective around the base station 30 and manages the cell 35.

The mobile terminal 10 connects to the cell 35 managed by the base station 30 and transmits / receives data such as communication traffic and control traffic to / from the base station 30.
The base station 30 transmits and receives data to and from the mobile communication core network 50 connected via the wired link 40.

  The mobile communication core network 50 includes a switching center (not shown) and a server device, and is connected to the base station 30 via the wired link 40 and is connected to the external network 70 via the wired link 60. Data is transmitted to and received from the external network 70.

  The network management system 90 is connected to the base station 30 via the wired link 80 and is connected to the mobile communication core network 50 via the wired link 81 to monitor the quality, failure monitoring, and configuration management of the wireless communication system. I do.

  In such a wireless communication system, it is required to appropriately set the wireless parameters of the base station 30 in order to satisfy the required wireless quality throughout the service area. Typical examples of the radio parameters include total transmission power for each cell, tilt angle of the base station antenna in the vertical / horizontal plane, a list of handover candidate cells, a handover threshold, and the like.

  In a wireless communication system, services are provided by arranging cells across the entire service area. The mobile terminal 10 performs a handover process for switching the connection destination cell when moving from the connection destination cell to another cell. In the following, “handover” is expressed as “HO”.

  HO is realized as follows. First, the radio quality of the connection destination cell and the HO candidate cell is measured for the mobile terminal 10, and when the radio quality of the connected cell deteriorates, the measurement information of the radio quality of the HO candidate cell is displayed. An instruction is given in advance to report to the base station 30 that manages the cell. Then, the base station 30 determines a HO destination cell at the time when there is a report from the mobile terminal 10.

  At this time, in order to reduce the load on the mobile terminal 10 and process the HO at a high speed, a method of limiting the HO destination cell candidates to only some HO candidate cells is generally used. Some of the HO candidate cells are Listed Cells registered in a list in which information is shared between the base station and each mobile terminal. Hereinafter, “Listed Cell” is referred to as “LC”. The list of LCs is referred to as “LC list”.

  The LC list is generated for each cell by the communication carrier, and is notified to the mobile terminal 10 from the base station 30 that manages the cell via the downlink. The mobile terminal 10 measures the radio quality of the LC and reports it to the base station 30.

  The base station 30 normally determines a HO destination cell from among the LCs that have received reports from the mobile terminal 10. Therefore, normally, the mobile terminal 10 cannot perform HO for cells other than the LC.

  Therefore, when LC is not properly selected, HO cannot be performed to an appropriate cell where good communication quality is obtained, and abnormal disconnection occurs in the middle, or radio quality deteriorates due to HO to an inappropriate cell. There is a risk of Therefore, generating an appropriate LC list is important for ensuring good radio quality.

  The optimization of the LC list has been performed by a professional engineer based on the result of a running test in the service area of the cellular communication system. However, in recent years, a technique for autonomously optimizing the LC list during operation of the cellular communication system has been proposed.

  Non-Patent Document 1 discloses preferentially registering a cell with a large number of measurement reports from a mobile terminal and a cell with a large number of HO trials of the mobile terminal by LC list registration.

  Non-Patent Document 1 describes an LC list update method using a list optimization system.

  FIG. 2 is a diagram for explaining the cell list update method described in Non-Patent Document 1. In this document, a mobile terminal measures and reports the received power of a pilot signal transmitted from a base station as radio quality.

  In the candidate cell list update method described in the document, the number of trials (a) of handover to the LC is counted for each LC. In addition, for each LC candidate cell that is an LC candidate cell, the number of times (n) reported from the mobile terminal that the received power of the pilot signal transmitted from the base station that manages the LC candidate cell is equal to or greater than the threshold is Aggregated.

  Then, the LC candidate cells whose report number (n) is equal to or greater than the threshold (ThAdd) are registered in the LC list in order from the cell with the largest report number (n). At the same time, the LC list whose number of trials (a) is less than or equal to the threshold (ThDel) is deleted from the LC list, whereby the LC list is updated.

D. Soldani and I.I. Ore, “Self-optimizing Neighbor Cell List for UTRAFDD Networks Using Detected SetReporting” in Proc. IEEE 65th Vehicular Technology Conference VTC2007, April 2007, pp. 199 694-698. 3GPP TS36.300 V12.5.0 (2015-03) (Internet <URL> http://www.3gpp.org/ftp/specs/archive/36_series/36.300/) 3GPP TS36.331 V12.5.0 (2015-03) (Internet <URL> http://www.3gpp.org/ftp/specs/archive/36_series/36.331/)

  However, if the LC list is optimized only by the number of HO implementations, a problem may arise when HO concentrates on a specific LC in the vicinity due to, for example, concentration of people at an event or the like.

  As described above, since the number of LCs is usually limited, in this case, LC candidate cells determined to have low priority cannot be registered in the candidate cell list, or once registered, they are deleted from the LC list. become. For example, in comparison with LC candidate cells in which HO is concentrated, other LC candidate cells with a small number of HO implementations are suitable as HO-destination base stations from the viewpoint of ensuring radio quality. May leak from the LC list. In that case, from the viewpoint of ensuring radio quality, HO cannot be performed for an appropriate cell as a HO-destination base station, and HO is attempted for an inappropriate LC. As a result, HO cannot be performed, or Even if it can be done, the communication quality after HO may deteriorate.

  On the other hand, even if the candidate cell list is appropriately created and the above problem is solved, the HO destination cell may not be appropriately selected. In this regard, a case where the procedures described in Non-Patent Document 2 and Non-Patent Document 3 are applied will be described as an example.

  In this procedure, the mobile terminal selects a cell to be a HO destination from the radio quality measurement information for each LC, and sets the cell's PCI (Physical Cell Identifier) to the base station that manages the currently connected cell. To report. Here, PCI is identification information for specifying (squeezing) cells to some extent. Only 504 symbol combinations are assigned to the PCI, and the PCI of the same symbol combination is generated by assigning the same symbol combination PCI to more than 504 cells. For this reason, the PCI cannot completely identify the cells, and becomes information for narrowing down. As a result, if a plurality of cells having PCIs having the same symbol combination are included in the candidate cell list, the base station may not be able to determine which LC the mobile terminal determines to be the HO destination. Arise. If the base station recognizes the same PCI LC that the mobile terminal should not have made as the HO destination as the HO destination, HO cannot be performed, or even if it can be performed, the communication quality after HO may deteriorate. To get.

  The present invention provides an information processing method and the like that can solve the above-described problems and improve the probability that a mobile terminal connected to a cell performs HO to a candidate cell that is expected to be suitable from the viewpoint of radio quality. The purpose is to do. Another object of the present invention is to provide an information processing method and the like that can improve the HO success probability of the mobile terminal or improve the quality of communication through the mobile terminal. .

  An information processing apparatus according to the present invention is an information processing apparatus for selecting a candidate cell that is a candidate of a trial destination cell that is a destination cell from which a terminal of a certain cell attempts a handover, and includes a derivation unit and an output unit. Prepare. The deriving unit derives positional relationship information indicating the closeness of the positional relationship between the certain cell and the candidate cell. The derivation unit also derives an evaluation result that gives a higher evaluation weight to a candidate cell that has been evaluated to have a higher degree of closeness in the positional relationship regarding the positional relationship information. The output unit outputs the evaluation result.

  The information processing method and the like of the present invention can increase the probability of HO trial to a base station that is expected to have good communication quality for a mobile terminal connected to a certain cell. As a result, the information processing method of the present invention can improve the HO success probability of the mobile terminal or improve the quality of communication through the mobile terminal.

1 is a conceptual diagram illustrating a configuration of a general wireless communication system. It is a figure explaining the LC list update method described in the nonpatent literature 1. FIG. It is a conceptual diagram showing the example of a structure of the information processing apparatus 300 of 1st embodiment. It is a conceptual diagram showing the example of a processing flow in the information processing apparatus 300 of 1st embodiment. It is a conceptual diagram showing the example of a processing flow in the information processing apparatus 300 of 2nd embodiment. It is a conceptual diagram showing the example of a structure of the information processing apparatus 200 of 3rd embodiment. 3 is a conceptual diagram illustrating a configuration example of a processing unit 210. FIG. It is a conceptual diagram (the 1) showing the example of a processing flow of the information processing apparatus 200 of 3rd embodiment. It is a conceptual diagram (the 2) showing the example of a processing flow of the information processing apparatus 200 of 3rd embodiment. It is a conceptual diagram showing the example of a structure of the information processing apparatus 400 of 4th embodiment. It is a conceptual diagram showing the example of a processing flow of the information processing apparatus 400 of 4th embodiment. It is a conceptual diagram showing the example of information processing of 4th embodiment in case selection conditions are that PCI of LC corresponds to the input PCI. It is a conceptual diagram showing the structure of the minimum information processing apparatus 301 of this invention.

<Explanation of terms>
In addition to the description of terms used so far in the present specification, main terms used in [Description of Embodiments] will be described below.
The “original cell” refers to a cell that is a source of performing HO with respect to the HO for evaluating whether it is appropriate to perform HO.
The “destination cell” refers to a cell that is a destination for performing HO with respect to the HO for evaluating whether it is appropriate to perform HO.
“Destination cell list” refers to a list of all destination cells.
<First embodiment>
This embodiment is an embodiment of an information processing apparatus for deriving an evaluation result that gives a higher evaluation weight to a destination cell that has been evaluated to have a closer positional relationship with the original cell. It is.
[Configuration and operation]
FIG. 3 is a conceptual diagram illustrating the configuration of the information processing apparatus 300 according to the present embodiment. The information processing apparatus 300 is an apparatus that evaluates the suitability of the destination cell as a destination to perform HO from the source cell for the mobile terminal connected to the source cell.

  The information processing apparatus 300 includes a specifying unit 320, a derivation unit 330, and an output unit 340.

  The specifying unit 320 specifies one previous cell.

  The deriving unit 330 evaluates the suitability of the destination cell identified by the identifying unit 320 as the destination where the mobile terminal connected to the source cell performs HO, and the evaluation result (hereinafter referred to simply as “evaluation result”). Derived). A method for evaluating the HO suitability at this time will be described later. The evaluation result is sent to the output unit 340.

The output unit 340 outputs the evaluation result sent from the derivation unit 330.
[Processing flow]
FIG. 4 is a conceptual diagram illustrating a processing flow in the information processing apparatus 300 according to the present embodiment.

  First, in S101, the specifying unit 320 specifies one destination cell.

  Next, in S102, the deriving unit 330 obtains information indicating the closeness of the positional relationship between the original cell and the destination cell specified in S101. It is assumed that the original cell is specified before this processing. Hereinafter, information representing the closeness of the positional relationship between the original cell and the destination cell is referred to as “positional relationship information”. The positional relationship information may be anything as long as it represents the closeness of the positional relationship between the source cell and the destination cell. The contents include, for example, the distance between the base station of the original cell and the base station of the destination cell, the overlapping condition such as the overlap area of the source cell and the destination cell, and the base cell of the destination cell for the reference signal sent by the source cell. Received signal strength. The received signal strength is included in the positional relationship information because there is a correlation that becomes stronger as the closeness increases as the distance between the base station of the original cell and the base station of the destination cell is closer.

  In S <b> 103, the deriving unit 330 derives an evaluation result that gives a higher evaluation weight to the destination cell that has evaluated that the positional relationship is closer to the positional relationship information. .

  As described in [Background Art], the suitability evaluation of the destination cell as the HO destination is evaluated based on the communication quality of the mobile terminal with the base station of each destination cell, the number of HOs executed in each destination cell, and the like. Examples are known. The information processing apparatus according to the present embodiment weights evaluations of contents representing the closeness of the positional relationship with respect to these evaluations. For example, when the evaluation result is a numerical value, the weighting of the evaluation is performed by adding a higher evaluation value weight when the positional relationship is closer (a kind of closeness).

  Alternatively, when the mobile terminal transmits the destination cell to which the mobile terminal should perform HO to the base station of the original cell by PCI as described in the section “Problems to be solved by the invention”, this PCI is a part of the evaluation result. is there. This is because the result of the mobile terminal evaluating that the PCI LC should be HO is expressed in PCI. In this case, the evaluation of the contents representing the closeness of the positional relationship is weighted for the LC narrowed down by the evaluation result PCI. In other words, if there are multiple destination cells with the same PCI, the destination cell having a higher evaluation of the content representing the closeness of the positional relationship is given a higher evaluation, and is selected with a higher probability as the HO destination cell. To be.

  The obtained evaluation result is sent to the output unit 340.

Finally, in S104, the output unit 340 outputs the evaluation result sent from the derivation unit 330.
[effect]
The information processing apparatus according to the present embodiment evaluates that the positional relationship between the base station of the source cell and the base station of the destination cell is closer to the evaluation result of the suitability of the destination cell as the HO destination. A higher evaluation weight is given to the destination cell that has been subjected to. For this reason, when the positional relationship information is evaluated to indicate that the positional relationship is closer, the evaluation result tends to be higher. Therefore, the probability that the destination cell that evaluates that the positional relationship is closer to the positional relationship information is selected as the HO destination cell is increased. Therefore, the information processing apparatus according to the present embodiment can increase the HO trial probability to a base station that is expected to have good communication quality for a mobile terminal that performs communication via a base station of a certain cell. As a result, the information processing apparatus of the present invention can improve the HO success probability of the mobile terminal or improve the quality of communication through the mobile terminal.
<Second embodiment>
The present embodiment is an embodiment related to an information processing apparatus that derives an evaluation result of a higher evaluation for a destination cell that has been evaluated that the positional relationship is closer to the positional relationship information. The information processing apparatus according to the first embodiment performs higher evaluation weighting on the destination cell that has been evaluated that the positional relationship is closer to the positional relationship information. The height is not specified. On the other hand, the information processing apparatus of this embodiment always gives a higher evaluation result to a destination cell that has been evaluated that the positional relationship is closer to the positional relationship information. Only for the destination cell that has been evaluated that the positional relationship information has the same closeness of the positional relationship, the level of the evaluation result is determined by evaluating the contents other than the positional relationship information.
[Configuration and operation]
The description of the configuration and operation of the information processing apparatus 300 according to the present embodiment is the same as the description of the configuration and operation of the information processing apparatus 300 according to the first embodiment illustrated in FIG.
[Processing flow]
FIG. 5 is a conceptual diagram illustrating a processing flow in the information processing apparatus 300 according to the present embodiment.

  The description of S101, S102, and S104 is the same as the description of the process denoted by the same number in FIG. Hereinafter, S203 will be described.

  In S <b> 203, the deriving unit 330 derives a higher evaluation result for the destination cell that has evaluated that the positional relationship is closer to the positional relationship information.

  The deriving unit 330 can derive the evaluation result by separately performing, for example, evaluating the closeness of the positional relationship with respect to the positional relationship information and evaluating the other contents. Then, the evaluation on the closeness of the positional relationship is given priority over the evaluation on the other contents. If the evaluations on the closeness of the positional relationship regarding the positional relationship information are equal, the suitability of the destination cell as the HO destination is evaluated by evaluating the other contents.

  The evaluation result is sent to the output unit 340.

  Here, the evaluation of the closeness of the positional relationship with respect to the positional relationship information does not need to be different for all the different contents representing the closeness of the positional relationship. That is, the evaluations may be made equally for all the contents representing the close positional relationship within a certain range. Typically, A that satisfies a certain condition that the positional relationship information indicates the closeness of the positional relationship and A that does not satisfy the condition may be evaluated as B. However, the evaluation for those having a closer positional relationship should be made higher.

For example, it is assumed that the positional relationship information is the distance between the base station of the original cell and the base station of the destination cell. In that case, C is evaluated when the distance is shorter than a certain value, and D is evaluated when the distance is not short, and the evaluation C is higher than the evaluation D.
[effect]
The information processing apparatus according to the present embodiment has a higher evaluation of the evaluation result of the suitability of the destination cell as the HO destination with respect to the destination cell that has evaluated that the positional relationship between the source cell and the destination cell is closer. give. For this reason, the destination cell that evaluates that the positional relationship is closer to the positional relationship information is selected as the cell of the HO-destination base station. Therefore, the information processing apparatus according to the present embodiment is expected to have better communication quality for a mobile terminal that performs communication via a base station of a certain cell. Can increase the probability of HO trials. As a result, the information processing apparatus of the present invention can improve the HO success probability of the mobile terminal or improve the quality of communication through the mobile terminal.
<Third embodiment>
The present embodiment is an embodiment related to an information processing apparatus that preferentially sets a destination cell having a closer positional relationship with respect to the positional relationship information as an LC.
[Configuration and operation]
FIG. 6 is a conceptual diagram showing the configuration of the information processing apparatus 200 of this embodiment.

  The information processing apparatus 200 includes a processing unit 210, a derivation unit 230, a list update unit 240, an output unit 250, and a recording unit 260.

  Typically, the information processing apparatus 200 is typically installed in a base station (not shown), but may be installed outside the base station.

  Information on the destination cell list or information on which the destination cell list is based is input to the processing unit 210. Hereinafter, the information that is the basis of the destination cell list is referred to as “the destination cell source information”. If the input information is destination cell source information, the processing unit 210 creates a destination cell list from the information.

  In addition, information regarding the number of HOs performed in each destination cell in the destination cell list is input to the processing unit 210. Information regarding the number of HOs is hereinafter referred to as “HO number information”. The HO number information is typically the number of HO trials performed in the previous cell within a unit time.

  Further, information regarding the position of each destination cell in the destination cell list is input to the processing unit 210. Information indicating the position of each destination cell is hereinafter referred to as “position information”. The processing unit 210 obtains positional relationship information between the base station 400 and the base station of each destination cell from the input location information about each destination cell.

  However, the position information may be position relation information. In this case, the position information is used as it is as the position relation information.

  The destination cell list, the HO number information of each destination cell, and the positional relationship information are sent to the recording unit 260, recorded, and sent to the derivation unit 230.

  The deriving unit 230 uses the destination cell list, the HO number information, and the positional relationship information sent from the processing unit 210 to obtain evaluation information regarding suitability as a HO destination for each destination cell. The evaluation information for each destination cell is sent to the recording unit 260 and recorded, and also sent to the list update unit 240.

  The list update unit 240 updates the LC list. At that time, among the previous cells, a predetermined number of previous cells with higher evaluation are registered in the LC list. The updated LC list is sent to the recording unit 260, recorded, and sent to the output unit 250.

  The output unit 250 outputs the LC list sent from the list update unit 240. The output LC list is recorded in the recording unit 260 and sent to a base station and a mobile terminal (not shown). The LC in the LC list is a candidate for further narrowing down the HO destination by the mobile terminal or the base station.

The recording unit 260 records information sent to the processing unit 210, the derivation unit 230, and the list update unit 240 based on instructions from the respective units. The recording unit 260 may be divided into a plurality of parts, or may be a part of another configuration of the information processing apparatus 100.

  FIG. 7 is a conceptual diagram illustrating a configuration example of the processing unit 210.

  The processing unit 210 includes a communication unit 140, a derivation unit 150, and a radio wave transmission unit 160.

  The radio wave transmission unit 160 includes a transmission antenna (not shown), and transmits a reference radio wave to each base station constituting the base station group 510 through the transmission antenna. Hereinafter, each base station constituting the base station group 510 is referred to as “another base station”.

  The communication unit 140 is connected to the network 900. A base station group 510 is connected to the network 900. The communication unit 140 can communicate with other base stations via the network 900. The other base station can receive the reference radio wave transmitted by the radio wave transmission unit 160, obtain the received signal strength, and send the obtained received signal strength to the communication unit 140 via the network 900. In the following, the received signal strength for the reference radio wave is referred to as “received strength”.

  The deriving unit 150 instructs other base stations to transmit information related to the reception intensity of the reference radio wave transmitted by the radio wave transmission unit 160 via the network 900 through the communication unit 140. In response to this instruction, the other base station sends information regarding the reception strength to the communication unit 140 via the network 900.

  The communication unit 140 sends information related to the reception intensity sent from the other base station to the derivation unit 150.

  The deriving unit 150 can create a destination cell list using the reception strength of another base station as the destination cell source information.

  For example, the deriving unit 150 sets a first threshold value of reception strength for determining whether to make a destination cell list based on an external input. Input from the outside at this time is performed via the network 900 through the communication unit 140, for example. Then, the deriving unit 150 sets only a cell whose reception intensity exceeds the first threshold as a destination cell. In this case, the reception intensity is used as the previous cell source information.

  The deriving unit 150 further instructs other base stations to transmit location information via the network 900 via the communication unit 140. In response to this instruction, the other base station sends its own location information to the communication unit 140 via the network 900.

  On the other hand, the communication unit 140 sends position information sent from another base station to the derivation unit 150.

  The deriving unit 150 obtains positional relationship information from the positional information sent from the communication unit 140. Alternatively, when the position information is position relation information, the derivation unit 150 uses the position information as position relation information as it is.

  For example, the deriving unit 150 can use the latitude and longitude of another base station as position information, and the distance between the base station 400 and another base station as position relation information. The fact that the distance is close suggests that there is a high possibility that the cell of the other base station and the cell of the base station 400 overlap or are close to each other. Such a cell may be suitable as a candidate for the mobile terminal to try HO because good communication quality is secured with the mobile terminal of the cell of the base station 400 at the time of trying HO. Is expensive.

  Alternatively, information indicating the position of the cell range of the other base station can be used as the position information, and an area where the cell range of the base station 400 and the cell range of the other base station overlap can be used as the position relationship information. The larger the overlapping area, the better the communication quality with the mobile terminal of the cell of the base station 400 at the time of trying HO, so the mobile terminal connected to the cell of the base station 400 This is because there is a high possibility that is suitable as a candidate to try HO.

  The information indicating the position of the cell range of the other base station is the information for deriving the position information, such as the latitude and longitude of the other base station, the installation angle of the antenna of the other base station, and the transmission intensity from the other base station. It may be obtained and obtained by the deriving unit 150 deriving from these values.

  The reception intensity of the other base station described above can also be used as positional relationship information that also serves as positional information. Since the reception strength has a correlation that the distance between the base station 400 and the base station of each destination cell becomes weaker, the positional relationship information indicating the closeness of the positional relationship between the cell of the base station 400 and each destination cell. It can be.

  Next, a method in which the deriving unit 150 obtains evaluation information based on positional relationship information will be described.

  First, the deriving unit 150 sets a condition relating to positional relationship information described later by external input. Input from the outside at this time is performed via the network 900 through the communication unit 140, for example. Then, the destination cell group of the positional relationship information that matches the condition is combined with the positional relationship information to form the first work list.

  For example, when the positional relationship information is the distance between the base station 400 and another base station, the condition is, for example, that the distance is equal to or less than (or less than) a threshold value for the distance.

  In addition, when the positional relationship information is an area where the cell range of the base station 400 overlaps the cell range of another base station, the above condition is, for example, that the area is equal to or smaller than (or less than) a threshold value for the area. It is to be.

  Further, when the positional relationship information is the reception intensity, the condition is, for example, that the reception intensity is equal to or greater than (or exceeds) a threshold for the reception intensity.

  Next, the deriving unit 150 evaluates other base stations using the number of HOs. The evaluation is performed, for example, by giving a higher evaluation to another base station having a higher HO number. The derivation unit 150 associates the other base station evaluated using the number of HOs with the evaluation result to form a second work list. Thereafter, the deriving unit 150 deletes other base stations that overlap the first work list from the second work list.

  Next, an example of an LC list update method performed in the list update unit 240 will be described.

  First, the list update unit 240 preferentially sets other base stations in the first work list as LCs. The cell of the other base station in the first working list is a cell that is likely to overlap or be close to the cell of the base station 400. Such a cell is used to suppress the possibility of being excluded from the LC because there is a high possibility that the communication quality when the mobile terminal is connected is high. When the number of destination cells in the first work list exceeds the number of LCs that can be registered (or additionally registered), the list update unit 240 preferentially selects LCs from destination cells with high evaluation. When the number of destination cells in the first work list is lower than the number of LCs that can be registered (or additionally registered), the list update unit 240 uses the second cell in the second work list for the lower registration frame. Of these, registration as LC is performed in descending order of evaluation.

  The deriving unit 150 may derive the evaluation value from the positional relationship information and the number of HOs.

The evaluation value in this case is, for example,
Evaluation value = A × (value representing positional relationship information) + (HO number)
And Here, A is a value for weighting the evaluation value of the value representing the positional relationship information. To increase the influence of the positional relationship information on the evaluation value, this value is increased.

The list update unit 240 preferentially selects LC from a destination cell having a high evaluation.
[Processing flow]
FIGS. 8 a and 8 b are conceptual diagrams illustrating an information processing example of the present embodiment performed in the derivation unit 150.

  First, in S401, the derivation unit 150 creates a destination cell list, and further creates a work list that is a copy thereof.

  Next, in S <b> 402, the deriving unit 150 sets a criterion for determining the positional relationship information.

In S403, the deriving unit 150 sets a threshold Th _HO regarding the number of HOs.

Next, in S404, the derivation unit 150 sets an upper limit value Th _N for the number of cells registered in the LC list.

  In S405, the derivation unit 150 acquires the number of HOs performed in each destination cell. This acquisition is performed, for example, when the deriving unit 150 requests transmission to the base station of each destination cell via the network 900 via the communication unit 140. In response to the request, the base station of each destination cell transmits the number of HOs performed in the mobile terminal of its own cell to the communication unit 140 via the network 900. The communication unit 140 sends the number of HOs sent to the derivation unit 150.

  Next, in S <b> 406, the deriving unit 150 records the HO number in each destination cell in the recording unit 260.

  On the other hand, in S407, the deriving unit 150 acquires the position information of the base station of each destination cell. This acquisition is performed, for example, when the deriving unit 150 requests transmission to the base station of each destination cell via the network 900 via the communication unit 140. In response to the request, the base station of each destination cell transmits its own location information to the communication unit 140 via the network 900. The communication unit 140 records the sent position information in the recording unit 260 and sends it to the derivation unit 150.

  In S408, the deriving unit 150 derives positional relationship information from the transmitted positional information. However, when the positional information is positional relation information, as in the case where the received intensity is used as positional relation information, the positional information is used as it is as positional relation information. The deriving unit 150 records the positional relationship information in the recording unit 260.

  Next, in S411, the derivation unit 150 identifies one destination cell from the work list created in S401.

  In S <b> 412, the deriving unit 150 acquires the HO number for the destination cell specified in S <b> 411 from the recording unit 260.

  In S413, the deriving unit 150 acquires the positional relationship information about the destination cell specified in S411 from the recording unit 260.

  In S414, the derivation unit 150 determines whether the acquired positional relationship information satisfies the determination criterion set in S402.

  If it is determined in S414 that the determination criterion set in S402 is satisfied, the process proceeds to S421.

  On the other hand, if it is not determined in S414 that the determination criterion set in S402 is satisfied, the process proceeds to S415.

In S415, the deriving unit 150 determines whether the HO number acquired in S412 is larger than the threshold Th _HO related to the HO number set in S403.

If it is determined in S415 that the number of HOs is greater than the threshold Th _HO , the process proceeds to S421.

On the other hand, if it is not determined in S415 that the number of HOs is greater than the threshold Th _HO , the process proceeds to S431.

  In S431, the derivation unit 150 deletes the identified destination cell from the work list. The deleted work list is recorded in the recording unit 260.

  In S432, the derivation unit 150 determines whether there is a previous cell in the work list.

  If it is determined in S432 that there is a previous cell in the work list, the deriving unit 150 proceeds to S411.

  On the other hand, if it is not determined in S432 that there is a previous cell in the work list, the derivation unit 150 ends this process.

  When the process proceeds to S421, the deriving unit 150 derives an evaluation for the destination cell specified in S411. The derived evaluation is recorded in the recording unit 260.

In S422, the deriving unit 150 determines whether the number of existing LCs is less than the upper limit value Th _{N of the} number of cells registered in the LC list set in S404.

In S422, deriving unit 150, when it is determined that is below the upper limit value Th _N of the number of cells, the process proceeds to S423.

  In S423, the deriving unit 150 adds the destination cell specified in S411 to the LC list. The LC list to which the identified candidate list is added is recorded in the recording unit 260.

  Then, the deriving unit 150 proceeds to S431.

On the other hand, in S422, if not determined is below the upper limit value Th _N number of cells, deriving unit 150, the process proceeds to S424.

  In S424, the derivation unit 150 identifies the LC having the lowest evaluation among the LCs already in the LC list.

  In S425, the deriving unit 150 determines whether the evaluation of the destination cell specified in S411 is higher than the evaluation of the lowest evaluation among the LCs already in the LC list.

  In S425, when the deriving unit 150 determines that the evaluation of the lowest LC among the LCs is higher than the evaluation, the deriving unit 150 proceeds to S426.

  In S426, the derivation unit 150 deletes the LC having the lowest evaluation score from the LC list. The deleted LC list is recorded in the recording unit 260.

  Then, the deriving unit 150 proceeds to S423.

On the other hand, in S425, when the deriving unit 150 does not determine that the evaluation of the lowest LC among the LCs is higher than the evaluation, the deriving unit 150 proceeds to S431.
[effect]
In the information processing method of the present invention, a mobile terminal that performs communication via a base station of a certain cell preferentially selects a destination cell having a close positional relationship, in which communication quality is expected to be favorable, as LC. And The LC is a list of destination cells that are candidates for the mobile terminal to attempt HO. Therefore, the information processing method and the like according to the present invention can increase the HO trial probability to a destination cell having a close positional relationship in which communication quality is expected to be favorable. As a result, the information processing method of the present invention can improve the HO success probability of the mobile terminal or improve the communication quality.
<Fourth embodiment>
In the present embodiment, when a plurality of LCs are narrowed down as candidates as a result of narrowing down LCs to be HO destinations from the LC list, LCs with higher positional relations regarding positional relation information are designated as HO destinations. It is embodiment about the information processing apparatus to select.
[Assumption]
In the information processing apparatus of the present embodiment, it is assumed that an LC list has already been created and positional relationship information has already been obtained for each LC, and these have been recorded.
[Configuration and operation]
FIG. 9 is a conceptual diagram showing the configuration of the information processing apparatus 400 of the present embodiment.

  The information processing apparatus 400 includes a processing unit 410, a recording unit 460, and an output unit 450.

  The information processing apparatus 400 is typically installed in a base station (not shown), but may be installed outside the base station.

  A condition (hereinafter referred to as “selection condition”) for narrowing down more appropriate cells as HO destinations is input to the processing unit 410. The selection condition is, for example, matching the input narrowing information. Here, “squeezed information” is information that narrows down LCs determined to be appropriate as HO destinations of the mobile terminals of the source cell by the outside of the information processing apparatus.

  The narrowing down information is typically the PCI for the LC determined to be appropriate as the HO destination of the mobile terminal by the mobile terminal of the original cell.

  The processing unit 410 searches for the LC recorded in the recording unit 460 using the input selection condition. Then, it is determined whether there are a plurality of LCs that match the selection condition. If there are a plurality of LCs, the positional relationship information for each LC is compared for closeness of the positional relationship. As a result, the LC determined to be the closest is selected as the HO destination LC of the mobile terminal, and the LC specifying information is sent to the output unit 450. Here, the LC identification information is identification information that is not the same as that of the other LC for one LC, and is typically E-UTRAN Cell described in Non-Patent Document 2 and Non-Patent Document 3. It is a Global Identifier (ECGI).

The output unit 450 outputs LC specific information.
[Processing flow]
FIG. 10 is a conceptual diagram illustrating an example of information processing according to the present embodiment.

  First, in S501, selection conditions are input to the processing unit 410.

  In step S <b> 502, the processing unit 410 reads information recorded in the recording unit 460 and searches for an LC that matches the selection condition.

  In step S503, the processing unit 410 reads the information recorded in the recording unit 460 and searches for positional relationship information for the LC that matches the selection condition.

  In step S504, the processing unit 410 selects, as an HO trial destination, an LC that is determined to have the highest positional relationship in the positional relationship information from LCs that match the selection condition. However, as a result of performing the process of S502, when there is only one LC that matches the input selection condition, the LC may be selected without determining the closeness of the positional relationship information. it can.

  In step S505, LC specific information about the selected LC is output.

  FIG. 11 is a conceptual diagram illustrating an information processing example of the present embodiment when the selection condition is that the PCI of the LC matches the input PCI.

  First, in S <b> 601, PCI is input to the processing unit 410.

  In step S <b> 602, the processing unit 410 reads information recorded in the recording unit 460 and searches for an LC that matches the input PCI.

  In step S <b> 603, the processing unit 410 reads information recorded in the recording unit 460 and searches for positional relationship information for an LC that matches the PCI.

  In step S <b> 604, the processing unit 410 selects, as an HO trial destination, an LC that is determined to have the highest positional relationship in the positional relationship information from the LCs that match the PCI. However, as a result of performing the process of S502, when there is only one LC that matches the input PCI, it is possible to select the LC without determining the closeness of the positional relationship for the positional relationship information. .

In step S605, the ECGI for the selected LC is output.
[effect]
When there are a plurality of LCs that match the selection condition, the information processing apparatus according to the present embodiment selects, from the plurality of LCs, the LC having the highest positional relationship information as the HO trial destination. The LC having the highest positional relationship regarding the positional relationship information has a high probability that the mobile terminal that performs HO can obtain sufficient received signal strength for the radio wave transmitted from the base station of the LC. Further, there is a high probability that the LC can obtain a sufficient received signal strength for the radio wave transmitted by the mobile terminal. Therefore, the information processing apparatus according to the present embodiment can increase the HO trial probability to a base station that is expected to have good communication quality for a mobile terminal that performs communication via a base station of a certain cell. As a result, the information processing apparatus of the present invention can improve the HO success probability of the mobile terminal or improve communication quality.

  FIG. 12 is a conceptual diagram showing the configuration of the information processing apparatus 301 having the minimum configuration according to the present invention.

  An information processing apparatus 301 having a minimum configuration according to the present invention is an information processing apparatus for selecting a candidate of a trial destination cell that is a destination cell from which a terminal of a certain cell attempts a handover, and includes a derivation unit 331 and an output unit 341 With.

  The deriving unit 331 derives positional relationship information representing the closeness of the positional relationship between the certain cell and the destination cell that is the candidate for the trial destination cell. The deriving unit 331 also derives an evaluation result that gives a higher evaluation weight to a destination cell that has been evaluated to have a higher degree of closeness in the positional relationship information.

  The output unit 341 outputs the evaluation result.

  The information processing method with the minimum configuration of the present invention has the effects described in [Effects of the Invention] by the above configuration.

  The information processing apparatus according to each embodiment described above can be realized by, for example, a computer including a CPU and a storage device and an information processing program that controls these hardware resources. Here, the CPU refers to a central processing unit. In this case, the CPU executes the processing described in each embodiment according to the information processing program stored in the storage device.

  Although the present invention has been described with reference to the preferred embodiments, the present invention is not necessarily limited to the above embodiments, and various modifications can be made within the scope of the technical idea.

  Moreover, although a part or all of said embodiment can be described also as the following additional remarks, it is not restricted to the following.

(Appendix A1)
An information processing method for selecting a candidate cell that is a candidate of a trial-destination cell that is a cell to which a terminal connected to a certain cell attempts a handover,
Deriving positional relationship information that represents the closeness of the positional relationship between the certain cell and the candidate cell, and for the candidate cell that has been evaluated that the positional relationship is more tight with respect to the positional relationship information, Derivation of evaluation results giving high evaluation weights,
Outputting the evaluation result;
Information processing method.

(Appendix A2)
The weighting is a weighting for deriving a higher evaluation result for a candidate cell that has been evaluated to have a higher degree of closeness of the positional relationship regarding the positional relationship information. Information processing method.

(Appendix A3)
From the candidate cells that have not been evaluated to be higher than the certain criterion, the weighting is a candidate cell that has been evaluated that the closeness of the positional relationship with respect to the positional relationship information is higher than a certain criterion, The information processing method described in appendix A1, which is weighting for deriving a higher evaluation result.

(Appendix A4)
The derivation unit further preferentially selects a cell from which a higher evaluation result is derived as a candidate cell, and the output unit outputs the selection result, any one of supplementary notes A1 to A3 Information processing method described in 1.

(Appendix A5)
The information processing method according to attachment A4, wherein a candidate cell having a high evaluation result is preferentially a shared candidate cell in which information is shared between the base station and the terminal.

(Appendix A6)
The weight is
Weighting performed on candidate cells narrowed down by determining that the candidate cells meet the conditions for evaluating the suitability of the candidate cells as the trial destination cells.
The information processing method described in appendix A3.

(Appendix A7)
The information processing method device according to attachment A6, wherein the condition is a condition obtained by the terminal.

(Appendix A8)
The condition is associated with the narrowing information to be sent by the terminal and the shared candidate cell with respect to narrowing information for narrowing down a plurality of shared candidate cells whose information is shared between the base station and the terminal. The information processing method according to any one of Supplementary Notes A3 to A5, wherein the narrowing-down information matches.

(Appendix A9)
The information processing method according to attachment A8, wherein the narrowing-down information is Physical Cell Identifier.

(Appendix A10)
The information processing method according to any one of Supplementary Notes A1 to A3, wherein the evaluation result is to preferentially select a cell with a higher evaluation as a candidate cell.

(Appendix A11)
The information processing method according to any one of Supplementary Notes A1 to A10, wherein a cell from which a higher evaluation result is derived is preferentially selected as a trial destination cell.

(Appendix A12)
The information processing method according to any one of Supplementary Note A1 to Supplementary Note A10, wherein the evaluation result is to preferentially select a higher evaluation cell as a trial destination cell.

(Appendix A13)
The shared candidate cell in which information is shared between the base station and the terminal is a candidate cell registered in a list with a limited number of registered shared candidate cells. Information processing method.

(Appendix A14)
The shared candidate cell in which information is shared between the base station and the terminal is described in Appendix A5 or Appendix A8, which is a Listed Cell registered in a list in which the number of shared candidate cells to be registered is limited Information processing method.

(Appendix B1)
An information processing apparatus for selecting a candidate cell that is a candidate of a trial destination cell that is a destination cell from which a terminal of a certain cell performs a handover trial,
Derivation of positional relationship information representing the closeness of the positional relationship between the certain cell and the candidate cell, and for the candidate cell that has been evaluated that the positional relationship is more tight with respect to the positional relationship information, A derivation unit for deriving an evaluation result given a high evaluation weight,
An output unit for outputting the evaluation result;
An information processing apparatus comprising:

(Appendix C1)
An information processing program for causing a computer to execute a process for selecting a candidate cell that is a candidate of a trial destination cell that is a destination cell from which a terminal of a certain cell attempts a handover,
Derived positional relationship information representing the closeness of the positional relationship between the certain cell and the candidate cell, and higher than the candidate cell that has evaluated that the positional relationship is higher in the positional relationship information A process for deriving an evaluation result giving an evaluation weight, and
Processing for outputting the evaluation results;
Processing program for causing a computer to execute a process including:

DESCRIPTION OF SYMBOLS 10 Mobile terminal 20 Wireless link 30 Base station 35 Cell 40, 60, 80, 81 Wired link 50 Mobile communication core network 70 External network 90 Network management system 140 Communication part 150 Derivation part 160 Radio wave transmission part 200, 300, 301, 400 Information Processing device 210, 410 Processing unit 230, 330, 331 Deriving unit 240 List updating unit 250, 340, 341, 450 Output unit 260, 460 Recording unit 320 Identification unit 510 Base station group 900 Network

Claims (8)

An information processing apparatus for selecting a candidate cell that is a candidate of a trial destination cell that is a destination cell from which a terminal of a certain cell performs a handover trial,
Deriving positional relationship information that represents the closeness of the positional relationship between the certain cell and the candidate cell, and for the candidate cell that has been evaluated that the positional relationship is more tight with respect to the positional relationship information, A derivation unit for deriving an evaluation result given a high evaluation weight,
An output unit for outputting the evaluation result;
Equipped with a,
Select the cell that derived the higher evaluation result as a candidate cell preferentially,
High candidate cell evaluation results, preferentially, the information processing apparatus information you select as a shared candidate cell that is shared between the base station of the one cell terminal. An information processing method for selecting a candidate cell that is a candidate of a trial-destination cell that is a cell to which a terminal connected to a certain cell attempts a handover,
Deriving positional relationship information that represents the closeness of the positional relationship between the certain cell and the candidate cell, and for the candidate cell that has been evaluated that the positional relationship is more tight with respect to the positional relationship information, Derivation of evaluation results giving high evaluation weights,
There line the output of the evaluation result,
Select the cell that derived the higher evaluation result as a candidate cell preferentially,
A candidate cell having a high evaluation result is preferentially selected as a shared candidate cell in which information is shared between a base station of the certain cell and the terminal .   The weighting is weighting for deriving a higher evaluation result for a candidate cell that has been evaluated to have a higher degree of closeness of the positional relationship regarding the positional relationship information. Information processing method.   From the candidate cells that have not been evaluated to be higher than the certain criterion, the weighting is a candidate cell that has been evaluated that the closeness of the positional relationship with respect to the positional relationship information is higher than a certain criterion, The information processing method according to claim 2, wherein weighting is performed to derive a higher evaluation result. The weight is
Weighting performed on candidate cells narrowed down by determining that the candidate cells meet the conditions for evaluating the suitability of the candidate cells as the trial destination cells.
The information processing method according to claim 3. The information processing method according to claim 5 , wherein the condition is a condition obtained by the terminal. The condition is
The terminal has sent, is to conform to the information to narrow down plurality of shared candidate cell in which information is shared by the communication between the base Chikyoku with the terminal,
The information processing method according to claim 5 or 6 . An information processing program for causing a computer to execute a process for selecting a candidate cell that is a candidate of a trial destination cell that is a destination cell from which a terminal of a certain cell attempts a handover,
Derived positional relationship information representing the closeness of the positional relationship between the certain cell and the candidate cell, and higher than the candidate cell that has evaluated that the positional relationship is higher in the positional relationship information A process for deriving an evaluation result giving an evaluation weight, and
Processing for outputting the evaluation results;
A process of preferentially selecting a cell from which a higher evaluation result is derived as a candidate cell;
An information processing program for causing a computer to execute a process including a process of preferentially selecting a candidate cell having a high evaluation result as a shared candidate cell in which information is shared between a base station of the certain cell and the terminal .

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