JP6334875B2 - Mobile terminal and positioning method selection method - Google Patents

Description

  The present invention relates to a mobile terminal and a positioning method selection method.

  Conventionally, as a positioning method for positioning the mobile terminal using the global positioning system, UE-B (UE-Based) positioning that performs positioning calculation on the mobile terminal, and positioning calculation on the positioning server side are performed. There is UE-A (UE-Assisted) positioning. Although UE-B positioning is superior to UE-A positioning in terms of power consumption, a positioning result cannot be obtained when positioning fails. On the other hand, although UE-A positioning can obtain a base station positioning (backup positioning) result when positioning by the global positioning system fails, a situation where the positioning result cannot be obtained does not occur, but a mobile terminal and a positioning server Because communication occurs between the network and the like, power consumption is large.

  As a method of selecting one positioning method suitable for the mobile terminal from the two positioning methods described above, for example, a positioning method to be performed in each time zone is set in advance, and one positioning method is selected according to the set contents There is a method (see, for example, Patent Document 1).

JP 2005-77226 A

  By the way, the above-described positioning method selection method is to set an appropriate positioning method in advance from the viewpoint of power consumption and positioning success probability in a place where a user is supposed to be present for each time slot. However, since the location of the user changes depending on the situation, the location where the user does not necessarily match the actual location, and a method of selecting a positioning method set in advance for each time zone, a positioning method suitable for the user is used. It may not be a choice.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mobile terminal capable of selecting an appropriate positioning method according to the actual situation of the user, and a positioning method selection method.

  A portable terminal according to the present invention is a portable terminal that selects one positioning method from a plurality of positioning methods using a global positioning system, and includes a history acquisition unit that acquires the latest positioning execution history, and a history acquisition unit. Selecting means for selecting a positioning method based on the acquired positioning execution history.

  A positioning method selection method according to the present invention is a positioning method selection method by a mobile terminal that selects one positioning method from a plurality of positioning methods using a global positioning system, and obtains the latest positioning execution history. And a selection step of selecting a positioning method based on the positioning execution history acquired in the history acquisition step.

  According to such a portable terminal and a positioning method selection method, a positioning method is selected based on the latest positioning execution history. By using the latest positioning execution history, an appropriate positioning method can be selected according to the actual situation of the user.

  In addition, the mobile terminal according to the present invention further includes a satellite number acquisition unit that acquires the number of visible satellites, the history acquisition unit acquires a positioning execution history including the number of visible satellites at the time of positioning, and the selection unit includes The positioning method is selected based on whether or not the number of visible satellites included in the positioning execution history is larger than the number of visible satellites acquired by the satellite number acquisition means.

  By comparing the number of visible satellites included in the positioning execution history with the number of visible satellites acquired by the satellite number acquisition means, an increase or decrease in the number of visible satellites since the most recent positioning execution is derived. By considering the actual increase or decrease in the number of visible satellites, it is possible to determine the success of positioning using the global positioning system with high accuracy, and as a result, it is possible to select an appropriate positioning method according to the actual situation of the user It becomes.

  When a positioning method is selected only from past positioning execution history, select an appropriate positioning method when the number of visible satellites changes significantly, for example, at the time of the first positioning that moved from outdoor to indoor. There is a risk that it will not be possible. In this regard, by acquiring the number of visible satellites and selecting a positioning method, an appropriate positioning method can be selected even when the number of visible satellites as described above changes significantly.

  In addition, the mobile terminal according to the present invention further includes a satellite number acquisition unit that acquires the number of visible satellites, the history acquisition unit acquires a positioning execution history including the number of visible satellites at the time of positioning, and the selection unit includes If the difference between the number of visible satellites included in the positioning execution history and the number of visible satellites acquired by the satellite number acquisition means is not more than a certain number, is the positioning using the global positioning system in the positioning execution history successful? Select a positioning method based on whether or not.

  The positioning result (success or failure) using the global positioning system is likely to coincide with the positioning result (success or failure) using the global positioning system in the latest positioning execution history. Therefore, by selecting the positioning method based on the result of positioning using the global positioning system in the latest positioning execution history and selecting the positioning method, the selection of the appropriate positioning method according to the actual situation of the user Is possible.

  In addition, the history acquisition unit of the mobile terminal according to the present invention acquires a plurality of consecutive recent positioning execution histories, and the selection unit continuously performs positioning using the global positioning system in the latest plurality of positioning execution histories. Select a positioning method based on whether or not

  If positioning using the global positioning system in the most recent positioning history has succeeded or failed continuously, positioning results using the global positioning system (success or failure) There is a high probability that it matches the results in the implementation history. Therefore, it is possible to select the appropriate positioning method according to the actual situation of the user by determining the success or failure of positioning based on the continuous results of positioning in the most recent positioning execution history and selecting the positioning method It becomes.

  Further, the history acquisition means of the mobile terminal according to the present invention acquires a plurality of consecutive recent positioning execution histories, and the selection means succeeds in positioning using the global positioning system in the latest plurality of positioning execution histories or A positioning method is selected based on whether the failure rate is equal to or higher than a certain rate.

  If the success or failure rate of positioning using the global positioning system in a plurality of positioning execution histories is more than a certain percentage, the positioning result (success or failure) using the global positioning system is the certain percentage It is highly likely that the above results are consistent. Therefore, by determining the success or failure of positioning based on whether or not the ratio of success or failure of positioning in a plurality of positioning execution histories is more than a certain ratio, the positioning method is selected, so that the actual situation of the user can be achieved. It is possible to select an appropriate positioning method according to the response.

  The portable terminal according to the present invention further includes search time determining means for determining a search time for the satellite number acquiring means to acquire the number of visible satellites, and the history acquiring means includes a plurality of consecutive positioning execution histories. The search time determining means obtains all the positions in the latest plurality of positioning execution histories when positioning using the global positioning system in the plurality of latest positioning execution histories has not succeeded or failed in succession. The search time is lengthened as compared with the case where positioning using the earth positioning system has succeeded or failed continuously.

  If it succeeds continuously, it is assumed that the satellite environment is good, and if it fails continuously, it is assumed that no visible satellites can be acquired because the user is indoors. In any case, it is considered that the number of visible satellites can be obtained with high accuracy even if the search time for obtaining the number of visible satellites is shortened. Thus, the power consumption can be reduced by shortening the search time. On the other hand, the satellite environment can be assumed to be unstable if the most recent positioning results are not succeeding or failing continuously, such as failure after success or success after failure. By increasing the search time, the accuracy of obtaining the number of visible satellites can be improved. Therefore, by dynamically changing the search time based on whether positioning has succeeded or failed continuously, the search time can be set appropriately according to the situation, reducing power consumption and the number of visible satellites Improve acquisition accuracy.

  According to the present invention, it is possible to select an appropriate positioning method according to the actual situation of the user.

It is a figure which shows the position positioning image of the portable terminal using a global positioning system. It is a figure which shows the system configuration | structure of the position positioning system which concerns on this embodiment. It is a block diagram which shows the function of the portable terminal which concerns on this embodiment. FIG. 4A is a table showing a DB structure of a mobile terminal, FIG. 4A shows a positioning execution history stored in the positioning history DB, and FIG. 4B shows a search time stored in the search time DB. It is a figure which shows the hardware constitutions of the portable terminal which concerns on this embodiment. It is a flowchart which shows the positioning system selection process of the portable terminal which concerns on this embodiment. It is a figure which shows the operation example of the conventional position positioning using a global positioning system. It is a figure which shows the operation example of the position positioning using a global positioning system based on this embodiment. It is a figure for demonstrating the effect which makes search time different.

  Embodiments according to the present invention will be described below with reference to the drawings. Where possible, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  The mobile terminal according to the present embodiment selects one positioning method from a plurality of positioning methods using a global navigation system (GNSS: Global Navigation Satellite System). More specifically, the most recent positioning execution history The positioning method is selected based on the above.

  As a positioning method using GNSS (GNSS positioning), UE-B (UE-Based) positioning that performs positioning calculation on a mobile terminal, and UE-A (UE-Assisted) positioning that performs positioning calculation on the positioning server side There is. UE-B positioning and UE-A positioning will be described with reference to FIG.

  FIG. 1 is a diagram showing a position positioning image of a mobile terminal using the global positioning system. In the portable terminal, the application instructs the GNSS positioning API (Application Programming Interface) of the GNSS chip to select either UE-B positioning or UE-A positioning.

  When performing UE-B positioning, a UE-B positioning request is made to the SLP (SUPL Location Platform) from the GNSS chip of the mobile terminal, and the SLP performs base station positioning to the GMLC (Gateway Mobile Location Center). Request. Then, GNSS assist data including the base station positioning result by GMLC and the satellite navigation message is transmitted from the SLP to the mobile terminal, and the mobile terminal performs GNSS positioning calculation based on the GNSS assist data.

  On the other hand, when performing UE-A positioning, a UE-A positioning request is made to the SLP from the GNSS chip of the mobile terminal, and the acquisition result of the GNSS signal observed on the mobile terminal side is included in the SLP A GNSS positioning calculation is performed based on the GNSS measurement data. When the GNSS positioning calculation is successful, the GNSS positioning calculation result is transmitted to the mobile terminal, and when the GNSS positioning calculation is unsuccessful, the base station positioning result acquired by the SLP from the GMLC is transmitted to the mobile terminal.

  Thus, since UE-B positioning performs GNSS positioning calculation based on GNSS assist data in a mobile terminal, a positioning result cannot be obtained when the GNSS positioning calculation fails.

  On the other hand, in the UE-A positioning, the base station positioning result acquired by the GMLC is transmitted to the mobile terminal even when the GNSS positioning calculation fails in the SLP. Therefore, unlike UE-B positioning, a situation where a positioning result cannot be obtained when a GNSS positioning calculation fails cannot occur. However, since communication between the mobile terminal and the SLP and GMLC occurs every time positioning is performed, the UE-A positioning consumes more power than the UE-B positioning. Thus, UE-A positioning and UE-B positioning have merits and demerits, respectively, and an appropriate positioning method is different depending on the circumstances.

  In the mobile terminal according to the present embodiment, the success / failure of the GNSS positioning calculation is determined from the latest positioning execution history, and based on the determination result, an appropriate one of UE-B positioning and UE-A positioning is selected. select. Thus, by using the latest positioning execution history, it is possible to select an appropriate positioning method according to the actual situation of the user. Hereinafter, detailed functions of the mobile terminal according to the present embodiment and the position positioning system including the mobile terminal will be described.

  FIG. 2 is a diagram showing a system configuration of the position positioning system according to the present embodiment.

  As shown in FIG. 2, the positioning system 50 includes a mobile terminal 1, an eNodeB (evolved Node B) 51, an ESP-GW (EPC Seving and PDN GateWay) 52, an SLP 53, a GMLC 54, and a BTS (Base A transceiver station (RNC) 55, a radio network controller (RNC) 56, and a serving general packet radio service support node (SGSN) 57 are provided.

  Among the devices described above, the eNodeB 51 is an LTE network device, and the BTS 55 and the RNC 56 are 3G network devices. In general, the LTE area 25 and the 3G area 30 overlap (overlay).

  In the present embodiment, the mobile terminal 1 is located in either the LTE area 25 or the 3G area 30 described above. The mobile terminal 1 is a mobile communication terminal that can communicate by being in the LTE network or the 3G network, and is, for example, a mobile phone or a tablet PC. The mobile terminal 1 is a mobile terminal that selects one positioning method from a plurality of positioning methods using GNSS positioning, specifically, UE-A positioning and UE-B positioning. Detailed functions of the mobile terminal 1 related to positioning method selection will be described later.

  The eNodeB 51 is a radio base station and a communication control device having a radio access control function. The eNodeB 51 has, as basic functions, an admission control function when a call is made from the mobile terminal 1 and a paging function for calling the mobile terminal when an incoming call is received from another mobile terminal.

  Further, the eNodeB 51 forms the LTE coverage area 25, and when the mobile terminal 1 is within the LTE coverage area 25, the eNodeB 51 and the mobile terminal 1 perform wireless communication according to the LTE scheme. Can do. The portable terminal 1 communicates with an MME (not shown), an SLP 53, a GMLC 54, and the like that are higher-level devices of the eNodeB 11 via the eNodeB 11.

  The ESP-GW 52 is a gateway that relays user data packets and connects to a network such as the Internet. The ESP-GW 52 has both functions of an S-GW (Serving Gateway) that is a gateway that handles user data packets and a P-GW (Packet Date Network Gateway) that is a gateway for connecting to an external network. ing.

  The SLP 53 has a function of generating GNSS assist data and transmitting it to the mobile terminal 1 when performing UE-B positioning. The GNSS assist data includes a base station positioning result and a satellite navigation message. The base station positioning result is the approximate position information of the mobile terminal 1 and includes the latitude, longitude, and error where the mobile terminal 1 is located. The SLP 53 requests the GMLC 54 to acquire approximate position information that is a base station positioning result.

  The satellite navigation message is information necessary for the GNSS positioning calculation by the mobile terminal 1, and includes satellite clock correction parameters, ephemeris data (detailed orbit information of the satellite), ionosphere correction parameters, satellite health status, almanac data (satellite Rough orbit information) and the like. The SLP 53 acquires a satellite navigation message from an assist data provider (not shown) that manages satellite information.

  Further, the SLP 53 has a function of performing a GNSS positioning calculation based on the GNSS major data transmitted from the mobile terminal 1 when performing UE-A positioning. When the GNSS positioning calculation by the SLP 53 is successful, the GNSS positioning calculation result is transmitted to the portable terminal 1 as the positioning result of the portable terminal 1. On the other hand, when the GNSS positioning calculation by the SLP 53 fails, the base station positioning result acquired by the SLP 53 from the GMLC 54 is transmitted to the mobile terminal 1 as the positioning result of the mobile terminal 1.

  The GMLC 54 has a function of receiving a base station positioning request (approximate position information acquisition request) from the SLP 53 and performing base station positioning. Specifically, the GMLC 54 makes a base station positioning request to the RNC 56 for the 3G network and eSMLC (not shown) for the LTE network, and acquires the positioning result of the mobile terminal 1 from these devices. to manage. The GMLC 54 and the SLP 53 may be the same device or different devices.

  The BTS 55 is a radio base station connected to the RNC 56. The BTS 55 forms the 3G coverage area 30, and when the mobile terminal 1 is in the 3G coverage area 30, the BTS 55 and the mobile terminal 1 can perform wireless communication according to the 3G communication method. it can. The mobile terminal 1 communicates with the RNC 56, the SLP 53, the GMLC 54, and the like that are higher-level devices of the BTS 55 via the BTS 55.

  The RNC 56 is a communication control device having a radio access control function, and is provided corresponding to the BTS 55. The RNC 56 performs processing related to wireless communication of the mobile terminal 1 located in the 3G located area 30 formed by the BTS 55. Further, the RNC 56 performs position positioning of the mobile terminal 1 in response to a base station positioning request from the GMLC 54.

  The SGSN 57 is a device that sets a session for packet communication and controls packet switching. The SGSN 57 has a GGSN (Gateway GPRS Support Node) function in the same apparatus for performing user authentication during packet communication.

  Next, details of functions related to positioning method selection of the mobile terminal 1 will be described with reference to FIGS. 3 and 4. FIG. 3 is a block diagram illustrating functions of the mobile terminal according to the present embodiment. FIG. 4 is a table showing the DB structure of the mobile terminal, where (a) shows the positioning execution history stored in the positioning history DB, and (b) shows the search time stored in the search time DB.

  As shown in FIG. 3, the mobile terminal 1 has a function implemented in the application 10 of the mobile terminal 1 and a function implemented in the GNSS chip 20 attached to the mobile terminal 1 as functions related to positioning method selection. I have.

  As functions implemented in the application 10, the mobile terminal 1 includes a history acquisition unit 11, a positioning history DB 12, a search time determination unit 13, a search time DB 14, a satellite number acquisition unit 15, a selection unit 16, and a timer. A control unit 17, a positioning process starting unit 18, and an assist data storage unit 19 are provided. The UE-A positioning execution unit 21 and the UE-B positioning execution unit 22 are provided as functions implemented in the GNSS chip 20.

  The history acquisition unit 11 is a history acquisition unit that acquires the latest positioning execution history. The history acquisition unit 11 acquires a positioning execution history from the positioning history DB 12. Here, the latest positioning execution history refers to a positioning execution history acquired within a range of, for example, several seconds to several minutes retroactively from the present time.

  Moreover, the history acquisition unit 11 acquires a plurality of consecutive positioning execution histories. Here, in addition to the positioning execution history acquired at the time closest to the current time, one or more positioning execution histories acquired at the time closest to the current time are included in the plurality of positioning execution histories most recently. .

  The history acquisition unit 11 acquires a positioning execution history including the number of visible satellites at the time of positioning execution related to the positioning execution history. Here, the number of visible satellites is the number of GPS satellites that are located in the sky at a reception point in a mobile terminal that performs GNSS positioning and can be observed at the reception point.

  The acquisition of the positioning execution history by the history acquisition unit 11 is performed together with the positioning timing when GNSS positioning is performed at regular activation (predetermined intervals) such as auto GNSS. In the case of auto GNSS, for example, GNSS positioning is performed at intervals of 5 minutes. Acquisition of the positioning execution history at such a predetermined interval is performed by the timer control unit 17 controlling the positioning process starting unit 18 and the positioning process starting unit 18 starting the history acquiring unit 11 at a predetermined interval. Is called. The history acquisition unit 11 inputs the acquired positioning execution history to the search time determination unit 13 and the selection unit 16.

  The positioning history DB 12 is a database that stores a positioning execution history. As shown in FIG. 4A, the positioning history DB 12 stores a history number, positioning time, GNSS positioning result, cell information, positioning method, user information, and number of search satellites for each positioning execution history. Yes.

  In the history number, a number is set so that the new positioning execution history becomes a lower number. The time at which positioning is performed is set as the positioning time. In the GNSS positioning result, information indicating whether the GNSS positioning calculation has succeeded or failed is set. In the cell information, information indicating a base station area in which the user is located, such as a cell ID, is set. As the positioning method, the method of positioning performed is set. That is, either UE-A positioning or UE-B positioning is set. In the user information, information (such as MSISDN) that identifies the user of the mobile terminal related to the positioning execution history is set. As the number of search satellites, the number of visible satellites at the time of positioning is set.

  The search time determination unit 13 is search time determination means for determining a search time for the satellite number acquisition unit 15 to acquire the number of visible satellites. The search time determination unit 13 determines the search time based on whether or not the GNSS positioning results in the plurality of consecutive positioning execution histories input by the history acquisition unit 11 have succeeded or failed continuously. To do. The search here is a satellite search for the satellite number acquisition unit 15 to acquire the number of visible satellites used for selection of the positioning method by the selection unit 16, and is a satellite search for performing a GNSS positioning calculation. Is different. The satellite search time for performing the GNSS positioning calculation is a time during which sufficient satellites for the positioning calculation can be acquired.

  For example, the search time determination unit 13 sets the search time T1 as a relatively short search time when the last five consecutive positioning execution histories have succeeded and have failed continuously. . On the other hand, when success or failure is not continuous, that is, when both success and failure are included in the plurality of consecutive positioning execution histories, the normal search time T2 with a relatively long search time is set. . Specifically, the shortened search time T1 is 1 to 5 seconds, and the normal search time T2 is 30 seconds or more (more specifically, about 30 to 60 seconds).

  The search time DB 14 is a database that stores a search time conversion table for converting the shortened search time T1 or the normal search time T2 derived by the search time determination unit 13 based on the positioning execution history into an actual search time.

  As shown in FIG. 4B, in the search time conversion table, the actual search time corresponding to the shortened search time T1 is 2 seconds, and the actual search time corresponding to the normal search time T2 is 30 seconds. Each is remembered. Such a search time conversion table may be set for each user.

  The search time determination unit 13 refers to the search time DB 14 to determine the search time from the shortened search time T1 or the normal search time T2, and inputs the search time to the satellite number acquisition unit 15.

  The satellite number acquisition unit 15 is a satellite number acquisition unit that acquires the number of visible satellites. The satellite number acquisition unit 15 acquires the number of visible satellites by capturing the GPS signal for the search time input by the search time determination unit 13. The satellite number acquisition unit 15 inputs the acquired number of visible satellites to the selection unit 16.

  The selection unit 16 is a selection unit that selects a positioning method based on the positioning execution history input by the history acquisition unit 11. The selection unit 16 selects either UE-A positioning or UE-B positioning as a selection method.

  Specifically, the selection unit 16 performs positioning based on whether the number of visible satellites included in the positioning execution history input to the history acquisition unit 11 is greater than the number of visible satellites acquired by the satellite number acquisition unit 15. Select a method. When the number of visible satellites included in the positioning execution history is larger than the number of visible satellites acquired by the satellite number acquisition unit 15, the selection unit 16 determines that the satellite environment is bad and the success probability of the GNSS positioning calculation is low. The UE-A positioning that can obtain the result of the base station positioning even when the GNSS positioning calculation fails is selected.

  On the other hand, when the number of visible satellites acquired by the satellite number acquisition unit 15 is larger than the number of visible satellites included in the positioning execution history, it is determined that the satellite environment is good and the success probability of the GNSS positioning calculation is high, and the selection unit 16 selects UE-B positioning which can suppress power consumption.

  Note that the selection unit 16 increases or decreases the number of visible satellites described above only when the difference between the number of visible satellites included in the positioning execution history and the number of visible satellites acquired by the satellite number acquisition unit 15 is a certain number or more. Select the positioning method based on.

  The selection unit 16 determines the positioning when the difference between the number of visible satellites included in the positioning execution history input to the history acquisition unit 11 and the number of visible satellites acquired by the satellite number acquisition unit 15 is not a certain number or more. A positioning method is selected based on whether or not the GNSS positioning calculation in the execution history is successful. The selection unit 16 may determine whether or not the GNSS positioning calculation is successful for only the positioning implementation history with the positioning scheme being UE-B positioning, or the positioning scheme is UE-B positioning. And those having a positioning method of UE-A positioning may be targeted. In addition, when UE-A positioning is performed, it can be determined whether or not the GNSS positioning calculation is successful based on the error radius included in the positioning result received from the SLP 53. That is, when the error radius is relatively small, the selection unit 16 can determine that the positioning result is obtained by GNSS positioning with high positioning accuracy, and that the GNSS positioning calculation is successful. When the error radius is relatively large, the selection unit 16 can determine that the positioning result is obtained by base station positioning with low positioning accuracy, and that the GNSS positioning calculation has failed.

  Specifically, the selection unit 16 selects UE-B positioning when the GNSS positioning calculation in the positioning execution history is successful, and UE- when the GNSS positioning calculation in the positioning execution history fails. Select A positioning.

  In this case, the selection unit 16 may select a positioning method based on whether or not the GNSS positioning calculation in the latest plurality of positioning execution histories input to the history acquisition unit 11 has succeeded continuously. . Here, “success in success” means success in two or more times.

  Further, the selection unit 16 selects a positioning method based on whether the success or failure rate of the GNSS positioning calculation in the plurality of latest positioning execution histories input to the history acquisition unit 11 is equal to or higher than a certain rate. May be. Here, the certain ratio or more is, for example, 75% or more.

  When selecting the UE-A positioning as the positioning method, the selecting unit 16 inputs the fact to the UE-A positioning performing unit 21. Moreover, the selection part 16 inputs that to the UE-B positioning implementation part 21, when selecting UE-B positioning as a positioning system.

  The UE-A positioning execution unit 21 has a function of transmitting GNSS major data to the SLP 53 and causing the SLP 53 to perform GNSS positioning calculation. The GNSS major data includes a result of capturing the GNSS signal observed by the mobile terminal 1.

  Further, the UE-A positioning execution unit 21 receives the positioning result from the SLP 53 and stores it in the positioning history DB 12 as the positioning execution history. Here, the positioning result received by the UE-A positioning execution unit 21 from the SLP 53 is the GNSS positioning calculation result when the GNSS positioning calculation by the SLP 53 is successful, and the SLP 53 when the GNSS positioning calculation by the SLP 53 fails. Is the base station positioning result acquired from the GMLC 54.

  The UE-B positioning execution unit 22 has a function of performing GNSS positioning calculation using GNSS major data and GNSS assist data received from the SLP 53. The GNSS assist data received from the SLP 53 is stored in the assist data storage unit 19. Since the GNSS assist data has a valid period, if the GNSS assist data is invalid after the valid period, the UE-B positioning execution unit 22 requests the SLP to transmit the GNSS assist data. To do. The UE-B positioning execution unit 22 stores the positioning result of the GNSS positioning calculation in the positioning history DB 12 as a positioning execution history.

  Next, the hardware configuration of the mobile terminal 1 will be described with reference to FIG. FIG. 5 is a diagram illustrating a hardware configuration of the mobile terminal according to the present embodiment. Each of the mobile terminals 1 shown in FIG. 3 physically includes, as shown in FIG. 5, one or a plurality of CPUs 101, a RAM 102 and a ROM 103 that are main storage devices, an input device 104 that is an input device, a display, and the like. The computer system includes an output device 105, a communication module 106 that is a data transmission / reception device, an auxiliary storage device 107 such as a semiconductor memory, and the like.

  Each function of the portable terminal 1 in FIG. 3 is obtained by reading one or a plurality of predetermined computer software on the hardware such as the CPU 101 and the RAM 102 shown in FIG. This is realized by operating the output device 105 and the communication module 106 and reading and writing data in the RAM 102 and the auxiliary storage device 107.

  Next, the positioning method selection process of the portable terminal 1 will be described with reference to FIG. FIG. 6 is a flowchart showing a positioning method selection process of the mobile terminal according to the present embodiment.

  As shown in FIG. 6, first, the history acquisition unit 11 acquires a plurality of latest positioning execution histories from the positioning history DB 12 (step S1). Subsequently, the search time determination unit 13 determines the search time for the satellite number acquisition unit 15 to acquire the number of visible satellites (step S2). Specifically, the search time determination unit 13 is based on whether or not the GNSS positioning results in a plurality of consecutive positioning execution histories input by the history acquisition unit 11 have succeeded or failed continuously. Determine the search time.

  Subsequently, the satellite number acquisition unit 15 performs a satellite search (capture of a GPS signal) for the search time determined by the search time determination unit 13, and acquires the number of visible satellites (step S3). Then, the selection unit 16 determines whether or not the difference between the number of visible satellites included in the positioning execution history and the number of visible satellites acquired by the satellite number acquisition unit 15 is a predetermined number or more (step S4).

  If it is determined in step S4 that the difference is greater than or equal to a certain number, is the number of visible satellites included in the positioning execution history by the selection unit 16 greater than the number of visible satellites acquired by the satellite number acquisition unit 15? It is determined whether or not (step S5).

  In step S5, when it is determined that the number of visible satellites included in the positioning execution history is larger than the number of visible satellites acquired by the satellite number acquisition unit 15, the selection unit 16 selects UE-A positioning as the positioning method. And UE-A positioning is implemented by the UE-A positioning implementation part 21 (step S6). Specifically, the UE-A positioning execution unit 21 transmits GNSS major data to the SLP 53 and causes the SLP 53 to perform GNSS positioning calculation.

  In step S5, if it is determined that the number of visible satellites included in the positioning execution history is not greater than the number of visible satellites acquired by the satellite number acquisition unit 15, the selection unit 16 sets the UE- B positioning is selected, and UE-B positioning is performed by the UE-B positioning execution unit 22 (step S7).

  On the other hand, if it is determined in step S4 that the difference is not equal to or greater than a certain number, the selection unit 16 determines whether or not the most recent GNSS positioning calculation is successful (step S8). When the GNSS positioning calculation is successful, the selection unit 16 selects UE-B positioning as the positioning method, and UE-B positioning is performed by the UE-B positioning performing unit 22 (step S7). When the GNSS positioning calculation has failed, the selection unit 16 selects UE-A positioning as the positioning method, and UE-A positioning is performed by the UE-A positioning execution unit 21 (step S6). .

  The positioning results in step S6 and step S7 are stored in the positioning history DB 12 by the UE-A positioning execution unit 21 or the UE-B positioning execution unit 22 (step S9).

  Next, the effect of the portable terminal 1 of this embodiment is demonstrated. According to the mobile terminal 1 of the present embodiment, a positioning method is selected based on the latest positioning execution history.

  Conventionally, there are UE-B positioning and UE-A positioning as GNSS positioning methods related to positioning of mobile terminals. In the UE-B positioning, the mobile terminal performs a GNSS positioning calculation based on the GNSS assist data transmitted from the SLP. As shown in FIG. 7 (a), when performing UE-B positioning, the GNSS positioning calculation fails during the period when the valid period of the GNSS assist data has elapsed, that is, the invalid period of the GNSS assist data. To do. In addition, when the GNSS major data cannot be obtained sufficiently, the GNSS positioning calculation fails. In cases where these GNSS positioning calculations fail, no positioning results can be obtained.

  On the other hand, in the UE-A positioning, the SLP performs GNSS positioning calculation based on GNSS measurement data including the result of capturing the GNSS signal observed on the mobile terminal side. In UE-A positioning, since the base station positioning result obtained by GMLC is transmitted to the mobile terminal even when GNSS positioning calculation in SLP fails, the positioning result is obtained when GNSS positioning calculation fails like UE-B positioning. The situation that cannot be done cannot happen. However, as shown in FIG. 7B, since communication between the mobile terminal and the SLP and GMLC occurs every time positioning is performed, UE-A positioning consumes less power than UE-B positioning. Will become bigger.

  From the above, selecting an appropriate positioning method from UE-A positioning and UE-B positioning according to the situation (actual situation of the user) at that time, acquisition of reliable positioning results, and power consumption It was important from the viewpoint of reduction.

  In this regard, in the mobile terminal 1 according to the present embodiment, the most recent positioning execution history is acquired, and the positioning method is selected based on the positioning execution history. Therefore, the GNSS positioning calculation is successful in consideration of the positioning execution history. It is possible to select a positioning method by determining whether or not the situation is easy to do.

  That is, as shown in FIG. 8, in consideration of the positioning execution history, when it is determined that the GNSS positioning calculation is likely to succeed, the UE-B positioning is performed to reduce the power consumption and the GNSS positioning. When it is determined that the operation is difficult to succeed, the UE-A positioning is performed, thereby obtaining a reliable positioning result.

  Further, the selection unit 16 selects a positioning method based on whether or not the number of visible satellites included in the positioning execution history is larger than the number of visible satellites acquired by the satellite number acquisition unit 15, so that the actual visible satellites are selected. The increase / decrease in the number is considered, and the success / failure of the GNSS positioning calculation can be determined with high accuracy.

  By selecting the positioning method based on the increase / decrease in the number of visible satellites, the number of visible satellites is reduced even when, for example, the GNSS positioning calculation is succeeded, and the vehicle suddenly enters the room. Accordingly, an appropriate positioning method (UE-A positioning in this case) can be selected.

  In addition, when the difference between the number of visible satellites included in the positioning execution history and the number of visible satellites acquired by the satellite number acquisition unit 15 is not a certain number or more, the selection unit 16 succeeds in the GNSS positioning calculation in the positioning execution history. The positioning method is selected based on whether or not it is. The result (success or failure) of the GNSS positioning calculation is highly likely to match the result (success or failure) of the GNSS positioning calculation in the latest positioning execution history. Therefore, it is possible to select an appropriate positioning method according to the actual situation of the user by determining the success or failure of positioning based on the result of the GNSS positioning calculation in the latest positioning execution history and selecting the positioning method.

  Moreover, the selection part 16 selects a positioning system based on whether the GNSS positioning calculation in the latest several positioning implementation log | history is succeeding continuously. When the GNSS positioning calculation in the most recent positioning execution histories succeeds or fails continuously, the result (success or failure) of the GNSS positioning calculation may match the results in the most recent positioning execution histories. high. Therefore, it is possible to select the appropriate positioning method according to the actual situation of the user by determining the success or failure of positioning based on the continuous results of positioning in the most recent positioning execution history and selecting the positioning method It becomes.

  Moreover, the selection part 16 selects a positioning system based on whether the success or failure rate of the GNSS positioning calculation in a plurality of recent positioning execution histories is a certain rate or more. When the success or failure rate of the GNSS positioning calculation in a plurality of recent positioning execution histories is equal to or higher than a certain rate, the result (success or failure) of the GNSS positioning calculation may match the result equal to or higher than the certain rate. high. Therefore, by determining the success or failure of positioning based on whether or not the ratio of success or failure of positioning in a plurality of positioning execution histories is more than a certain ratio, the positioning method is selected, so that the actual situation of the user can be achieved. It is possible to select an appropriate positioning method according to the response.

  In addition, when the GNSS positioning calculation in the latest plurality of positioning execution histories has not succeeded or failed continuously, the search time determination unit 13 performs positioning using the global positioning system in the latest plural positioning execution histories. The search time is increased as compared with the case where is continuously succeeding or failing. When the GNSS positioning calculation is continuously successful, it is assumed that the satellite environment is good. When the GNSS positioning calculation is continuously failed, the visible satellite cannot be acquired at all because the user is indoors. In any case, it is considered that the number of visible satellites can be obtained with high accuracy even if the search time for obtaining the number of visible satellites is shortened. Thus, the power consumption can be reduced by shortening the search time.

  On the other hand, the satellite environment can be assumed to be unstable if the most recent positioning results are not succeeding or failing continuously, such as failure after success or success after failure. By increasing the search time, the accuracy of obtaining the number of visible satellites can be improved. Therefore, by determining the search time based on whether positioning has succeeded or failed continuously, the search time can be set appropriately according to the situation, reducing power consumption and improving the acquisition accuracy of the number of visible satellites Can be realized. .

  With reference to FIG. 9, the effect of varying the search time will be described. As shown in FIG. 9, the search time, which is the time for acquiring the number of visible satellites by the satellite number acquisition unit 15, is set to the shortened search time T1 (1 to 5 seconds) and the normal search time T2 (30 seconds). There are two patterns in the above case. Normally, in order to select a positioning method based on the number of visible satellites, it is necessary to search for visible satellites for 30 seconds or more to obtain the number of visible satellites. Time is required for the pre-positioning process.

  Here, when the GNSS positioning calculation in the plurality of recent positioning execution histories succeeds or fails continuously, it is assumed that the satellite environment is good or the number of visible satellites cannot be obtained. The search time for acquiring the number of satellites is shortened search time T1 (1 to 5 seconds), and even if only the satellites that can be acquired instantaneously (that is, the satellites that are visible well) are acquired, the actual number of visible satellites Can be obtained with high accuracy. In this case, it is possible to reduce the power consumption and the time for the pre-positioning process.

  On the other hand, if the plurality of latest positioning results have not succeeded or failed in succession, it can be assumed that the satellite environment is unstable, so the search time for acquiring the number of visible satellites is the normal search time T2. By setting (30 seconds or more), the acquisition accuracy of the number of visible satellites can be improved. Even when the search time is set to the normal search time T2, communication between the mobile terminal 1 and the SLP 53 does not occur. Therefore, power consumption is small compared to UE-A positioning in which communication with the SLP 53 occurs. Become.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments. The present invention is modified without departing from the scope described in the claims or applied to others. It may be.

  For example, each function of the mobile terminal 1 has been described as having a function implemented in the application 10 and a function implemented in the GNSS chip 20. However, the present invention is not limited to this, and each function is included in either the application or the GNSS chip. May be implemented. Moreover, a positioning system is not limited to UE-A positioning and UE-B positioning, Other GNSS positioning may be sufficient.

  In addition, the mobile terminal acquires cell information (for example, cell ID) indicating the base station area in which the mobile terminal is located, and acquires only the positioning execution history that matches the cell information among the positioning execution histories stored in the positioning history DB. It is good to do. In addition, the search time may be determined only from the positioning execution history that matches the cell information.

DESCRIPTION OF SYMBOLS 1 ... Portable terminal, 10 ... Application, 11 ... History acquisition part, 12 ... Positioning history DB, 13 ... Search time determination part, 14 ... Search time DB, 15 ... Satellite number acquisition part, 16 ... Selection part, 17 ... Timer control , 18 ... Positioning processing activation unit, 19 ... Assist data storage unit, 20 ... GNSS chip, 21 ... UE-A positioning execution unit, 22 ... UE-B positioning execution unit, 25 ... LTE coverage area, 30 ... 3G presence Service area, 50 ... Positioning system, 51 ... eNodeB, 52 ... ESP-GW, 53 ... SLP, 54 ... GMLC, 55 ... BTS, 56 ... RNC, 57 ... SGSN.

Claims (5)

A mobile terminal that selects one positioning method from a plurality of positioning methods using a global positioning system,
History acquisition means for acquiring the latest positioning execution history;
Selection means for selecting a positioning method based on the positioning execution history acquired by the history acquisition means;
Satellite number acquisition means for acquiring the number of visible satellites related to the selection of the positioning method by the selection means;
The satellite number acquisition means comprises search time determination means for determining a search time for acquiring the number of visible satellites related to selection of a positioning method by the selection means,
The history acquisition unit, a positioning execution history includes the visible satellite number during positioning execution, the most recent plurality of continuous every few seconds, get,
The selection means selects a positioning method based on whether or not the number of visible satellites included in the positioning execution history is greater than the number of visible satellites acquired by the satellite number acquisition means,
The search time determining means, when positioning using the global positioning system in the latest plurality of positioning execution histories has not succeeded or failed continuously, the global positioning in the latest plurality of positioning execution histories The portable terminal which lengthens the said search time compared with the case where the positioning using a system is succeeding or failing continuously.   If the difference between the number of visible satellites included in the positioning execution history and the number of visible satellites acquired by the satellite number acquisition means is not a certain number or more, the selection means uses the global positioning system in the positioning execution history The mobile terminal according to claim 1, wherein a positioning method is selected based on whether or not the determined positioning is successful.   The portable terminal according to claim 2, wherein the selection unit selects a positioning method based on whether or not positioning using the global positioning system in the latest plurality of positioning execution histories is continuously successful. .   The selection means selects a positioning method based on whether a success or failure rate of positioning using the global positioning system in the plurality of positioning execution histories is equal to or greater than a certain rate. The portable terminal as described in. A positioning method selection method by a mobile terminal that selects one positioning method from a plurality of positioning methods using a global positioning system,
History acquisition step for acquiring the latest positioning execution history;
A selection step of selecting a positioning method based on the positioning execution history acquired in the history acquisition step;
A satellite number acquisition step of acquiring the number of visible satellites related to the selection of the positioning method in the selection step;
In the satellite number acquisition step, a search time determination step for determining a search time for acquiring the number of visible satellites related to the selection of the positioning method in the selection step, and
Wherein the history acquisition step, a positioning execution history visible satellite number during positioning execution is included, the most recent plurality of continuous every few seconds, get,
In the selection step, a positioning method is selected based on whether or not the number of visible satellites included in the positioning execution history is greater than the number of visible satellites acquired in the satellite number acquisition step,
In the search time determination step, if positioning using the global positioning system in the latest plurality of positioning execution histories has not succeeded or failed in succession, global positioning in the latest plurality of positioning execution histories A positioning method selection method in which the search time is lengthened as compared with a case where positioning using a system has succeeded or failed continuously.

Images