JP2005094634A - Area diagnostic method and apparatus using detailed call information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently estimate the distribution of call quality in each area in real time in a cellular communication system. <P>SOLUTION: Detailed call information of each of mobile terminals is collected via a base station. Besides, with respect to a plurality of base stations, a base station information file containing at least a local number of the base station and location information is created. The call quality of each mobile terminal, local numbers of the plurality of base stations near the mobile terminal and signal propagation time information are acquired from these detailed call information and base station information file. On the basis of the local number information and location information of the plurality of base stations near the mobile terminal and the signal propagation time information, the location of the mobile terminal is found. Thus found location information of the mobile terminal and the call quality information found from the detailed call information are correspondently outputted and plotted on a map. A parameter such as call quality is filtered and plotted on the map as needed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an area diagnosis technique using detailed call information, for example, a technique that enables real-time determination of an area having poor call quality using call detailed information in a cellular communication system.

  In the cellular radio communication system, base stations that can communicate with a plurality of mobile terminals are arranged in each area (cell) within a service area, and signals that are connected to these base stations and communicated via the base stations. And a central exchange office that exchanges In such a cellular communication system, the communication quality of each mobile terminal depends on, for example, in which area the base station is arranged and what value the transmission power of each base station is set to.

  Conventionally, the number and location of base stations to be placed in the service area of a cellular communication system is set up in advance according to a default placement plan, and each base station is actually operated to measure call quality in various areas. As a result, the layout plan was revised. The call quality is measured by mounting test equipment on an automobile, traveling around each area, measuring electric field strength, frame error rate (FER), and the like, and analyzing the measured data. Therefore, if it is determined that the call quality is poor at a certain place as a result of this measurement, measures such as increasing the power of the base station in the area or newly installing a base station have been taken.

  However, the conventional method of measuring each area with a test device installed in a car or the like, that is, the drive test, requires enormous time and effort to collect data such as call quality in each area. It was inefficient.

  Further, in a cellular communication system, for example, a CDMA communication system, the call quality varies greatly depending on traffic load, and tends to change depending on time and area. For this reason, it is preferable to simultaneously measure the data such as call quality in the entire service area of the cellular communication system, but this is physically impossible.

For this reason, conventionally, it has been necessary to collect data by running a car or the like equipped with test equipment over a wide area over a long period of time. However, even if data was collected over such a long time, data such as call quality in each area could not be obtained in real time. Furthermore, it was impossible to measure the call quality in the building or on the train in the drive test. Conventionally, a method for obtaining the position of each mobile terminal has been proposed, but a method for performing area diagnosis in real time by collectively processing the positions and call quality of many mobile terminals has not been proposed. It was.
JP 2001-83231 A JP 2002-236163 A

  The present invention makes it possible to collect call quality information and the like in each area efficiently, quickly and in real time in a cellular communication system.

In one aspect of the present invention, there is provided an area diagnosis method using call detailed information in a cellular communication system including a plurality of base stations that can communicate with a plurality of mobile terminals, and an exchange connected to the plurality of base stations. Provided, the method comprises:
(A) From call detailed information collected from a plurality of mobile terminals via a plurality of base stations in the exchange, call quality of a certain mobile terminal, station number information of a plurality of base stations near the mobile terminal, and the plurality Collecting signal propagation delay time information between the base station and the mobile terminal;
(B) for a plurality of base stations in the vicinity of the mobile terminal, collecting base station information including at least a base station number and base station position information;
(C) A procedure for obtaining the position of the mobile terminal based on station number information and position information of a plurality of base stations in the vicinity of the mobile terminal and signal propagation delay time information between the base stations in the vicinity of the mobile terminal and the mobile terminal ,
(D) a procedure for outputting the location information and call quality information of the mobile terminal in association with each other;
(E) a procedure for performing the procedures (A) to (D) for a plurality of mobile terminals;
It is characterized by comprising.

  The procedure for determining the position of the mobile terminal is based on the difference in distance between the plurality of base stations near the mobile terminal and the mobile terminal from the signal propagation delay time information between the base stations near the mobile terminal and the mobile terminal. And the position of the mobile terminal can be obtained using the distance difference.

  The position of the base station in the base station information is represented by the latitude and longitude of the base station, the latitude and longitude are converted into orthogonal coordinates, and the converted orthogonal coordinates and signal propagation delay time information between the base station and the mobile terminal To obtain a distance difference between the base station and the mobile terminal, obtain orthogonal coordinates of the mobile terminal based on the distance difference, and convert the orthogonal coordinates of the mobile terminal to longitude and latitude to obtain position information of the mobile terminal Convenient.

In another aspect of the present invention, an area diagnosis method using call detail information in a cellular communication system including a plurality of base stations each capable of communicating with a plurality of mobile terminals, and an exchange connected to the plurality of base stations A program for causing a computer to execute is provided.
(A) From call detailed information collected from a plurality of mobile terminals via a plurality of base stations in the exchange, call quality of a certain mobile terminal, station number information of a plurality of base stations near the mobile terminal, and the plurality Collecting signal propagation delay time information between the base station and the mobile terminal;
(B) for a plurality of base stations in the vicinity of the mobile terminal, collecting base station information including at least a base station number and base station position information;
(C) A procedure for obtaining the position of the mobile terminal based on station number information and position information of a plurality of base stations in the vicinity of the mobile terminal and signal propagation delay time information between the base stations in the vicinity of the mobile terminal and the mobile terminal ,
(D) a procedure for outputting the location information and call quality information of the mobile terminal in association with each other;
(E) a procedure for performing the procedures (A) to (D) for a plurality of mobile terminals;
Is executed by a computer.

In still another aspect of the present invention, area diagnosis using detailed call information in a cellular communication system comprising a plurality of base stations each capable of communicating with a plurality of mobile terminals, and a switching center connected to the plurality of base stations An apparatus is provided, the apparatus comprising:
(A) From call detailed information collected from a plurality of mobile terminals via a plurality of base stations in the exchange, call quality of a certain mobile terminal, station number information of a plurality of base stations near the mobile terminal, and the plurality Means for collecting signal propagation delay time information between the base station and the mobile terminal;
(B) for a plurality of base stations in the vicinity of the mobile terminal, means for collecting base station information including at least a base station number and base station position information;
(C) Means for determining the position of the mobile terminal based on station number information and position information of a plurality of base stations in the vicinity of the mobile terminal and signal propagation delay time information between the plurality of base stations in the vicinity of the mobile terminal and the mobile terminal ,
(D) means for outputting location information of the mobile terminal and call quality information in association with each other;
(E) With respect to a plurality of mobile terminals, the means (A) to (D) are made to function and the position information and the call quality information are output in association with the plurality of mobile terminals,
It is characterized by comprising.

  According to the present invention, call quality information and the like in a cellular communication system can be efficiently monitored over a wide area in real time, and call quality measurement requires a lot of manpower for a long time as in the conventional method. do not do. Compared to the conventional method, it is possible to collect data such as call quality accurately and efficiently even in a room, in a train, or other places where a car cannot travel. Furthermore, even when the drive test is performed in an auxiliary manner, it is possible to perform a more efficient drive test by grasping an area with poor call quality in advance by the technique of the present invention. Furthermore, according to the present invention, data such as call quality in each area can be continuously monitored in real time.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a cellular communication system for carrying out an area diagnosis method using detailed call information according to an embodiment of the present invention. The system shown in FIG. 1 may be a CDMA mobile phone communication system, for example. The system of FIG. 1 includes a base station (BTS) 3, a mobile terminal (MT) 5, a central switching center (SC) 7, and a local computer 9.

  In FIG. 1, only one base station 3 is shown, but actually, the service area of the cellular communication system is divided into a plurality of areas, and one base station 3 is provided for each area. Yes. The plurality of base stations 3 are connected to the central exchange 7 via a predetermined communication link.

  Each base station 3 can communicate with a plurality of mobile terminals 5. That is, each mobile terminal 5 can communicate with another mobile terminal 5 via the base station 3 or a wired subscriber telephone (not shown) via the base station 3 and the central exchange 7. The central exchange 7 performs necessary telephone exchange operations and the like so that each mobile terminal 5 can communicate with or communicate with other mobile terminals. The local computer 9 is a data processing device connected to the central exchange 7 for carrying out the method of the present invention. However, the method according to the present invention can also be carried out by a data processing device in the central exchange 7.

  According to the present invention, for example, the following processing is roughly performed in the local computer 9 connected to the central exchange 7. First, for example, at the end of a call of each mobile terminal 5, call detailed information is transmitted from the mobile terminal 5 to the base station 3, and the base station 3 transmits the call detailed information to the central exchange 7. The central switching center 7 has a data processing function part called a data logger, and stores detailed call information transmitted from each mobile terminal 5 at the end of the call by this data logger.

  From the call detailed information (CDL: Call Detailed Log) stored in the central switching center 7 in this way, the local computer 9 obtains necessary data, for example, call quality information of each call, base station number, and mobile terminal Information necessary for estimating the position is retrieved into the memory of the local computer 9, that is, downloaded. Further, the local computer 9 creates a base station information file including predetermined information data from previously known base station information regarding the cellular communication system. This base station information file includes, for example, information indicating the station number and position of each base station.

  Based on these pieces of information, as will be described in detail later, a program (CAD tool: CDL Area Diagnostics Tool) built in the local computer 9 detects the position of each mobile terminal and the mobile terminal corresponding to that position. The corresponding call quality information is stored and output. The call quality information of the mobile terminal is, for example, a frame error rate (FER). In this way, information indicating the location and call quality of each mobile terminal is accumulated and output. Such information of each mobile terminal is plotted on a map, for example.

  For example, as shown in FIG. 2, a circle mark is attached to a location of a mobile terminal whose call quality is a predetermined value or higher, and a cross mark is plotted to a location of a mobile terminal whose call quality is worse than a predetermined value. That is, for a large number of mobile terminals, information indicating the position and call quality of each mobile terminal is plotted on a map.

  Then, as shown in FIG. 3, a poor quality area marked with a cross on the map is extracted, and the poor quality area is displayed and / or printed. Instead of plotting call quality for all mobile terminals as shown in FIG. 2, only mobile terminals having quality values in a predetermined range such as poor quality are extracted, that is, filtered and displayed on the map. May be. As a result, it is possible to easily know which area has a poor call quality in the service area of the cellular communication system.

  FIG. 4 shows a method for estimating the position of the mobile terminal (MT) in the above-described processing. As shown in the figure, the position of the mobile terminal (MT) is estimated from the positions of three or more base stations near the mobile terminal that can communicate with the mobile terminal (MT), for example, A, B, and C. can do. The mobile terminal (MT) transmits the call detail information (CDL) as described above at the end of the call, for example. This detailed call information is received at each of the base stations A, B and C and sent from the respective base stations A, B and C to the central exchange.

  The call detail information includes chip delay information in a CDMA cellular communication system, for example. This chip delay information is information indicating the propagation delay time of a signal sent from the mobile terminal (MT) to each base station. Therefore, the distance difference between the mobile terminal (MT) and the base station can be obtained from this propagation delay time information.

  Therefore, as shown in FIG. 4, when connecting the points where the distance between the mobile terminal (MT) and the base station A and the distance difference between the mobile terminal (MT) and the base station B become constant, a hyperbola HL1 is obtained. It becomes. That is, the hyperbola HL1 represents a curve in which the difference between the distance m1 between the mobile terminal (MT) and the base station A and the distance m2 between the mobile terminal (MT) and the base station B is constant. Similarly, a hyperbola HL2 is obtained by connecting points where the difference between the distance n1 between the mobile terminal (MT) and the base station A and the distance n2 between the mobile terminal (MT) and the base station C becomes constant. Therefore, the position of the mobile terminal (MT) can be obtained from the intersection of these hyperbolic curves HL1 and HL2 using the position information of each base station known in advance.

  In the present invention, when obtaining the position of each mobile terminal (MT), it is obvious that the above-described method may be used, or any other appropriate method may be used.

  Next, an area diagnosis method using detailed call information according to the present invention will be described in more detail with reference to FIGS. FIG. 5 is a flowchart showing a processing procedure of an area diagnosis method using detailed call information according to the present invention. First, in step 501 of FIG. 5, for example, the local computer 9 (FIG. 1) connected to the central exchange 7 (FIG. 1) uses the call detailed information (CDL) accumulated in the central exchange 7 to Download all or part of the call details that should be used to implement

  On the other hand, the local computer 9 creates a base station information file from previously known base station information. This base station information file is generated, for example, including the station number and position of each base station in association with each other, for example, latitude and longitude.

  On the other hand, the call quality of a certain mobile terminal, for example, the frame error rate (FER) is calculated from the detailed call information collected at step 501 at step 505. The call quality is calculated from the frequency of transmission of a power measurement request message (PMRM) in a CDMA cellular communication system, for example. That is, in a CDMA cellular communication system, when a mobile terminal enters an area where radio waves from a base station are weak or is located in a place where radio waves are weak, a PMRM is transmitted to the base station so as to increase transmission power. Therefore, the signal quality, for example, the above-mentioned FER can be estimated by the number of times the mobile terminal has sent this PMRM to the base station. That is, it is possible to estimate the downlink FER based on the PMRM transmission frequency.

  In addition to FER, any parameter can be used alone or in combination as a call quality parameter. These parameters include, for example, the bit error rate (BER), the energy value (Ec / Io) of the carrier signal with respect to the disturbing signal, the signal-to-noise ratio (SNR), and the noise rise value (Noise Rise) that is the increase in the noise level. ), Data communication speed throughput, call duration, data volume, etc. can be used. Also, using parameters other than call quality, it is possible to know the distribution of each parameter for each area.

  Furthermore, in step 507, three base stations with which the mobile terminal can communicate are selected in order to estimate the position of the mobile terminal under consideration. For example, the three base stations further select two base stations in order of strong radio waves from the mobile terminal, in addition to the base station with which the mobile terminal is currently communicating. That is, three base stations near the mobile terminal are selected, and the numbers of these base stations are acquired, for example, stored in a predetermined memory area. Further, the propagation delay time information of the CDMA signal from the mobile terminal under consideration to these three base stations, that is, the phase delay information is also acquired from the detailed information of the downloaded call.

  In step 509, based on the three base station numbers selected in step 507, latitude and longitude information (latitude and longitude) of these three base stations is acquired from the base station information file.

  In step 511, the latitude and longitude information of these base stations is converted into orthogonal coordinate data.

  In step 513, from the signal propagation delay time information acquired in step 507 and the orthogonal coordinates of each base station obtained by the processing in step 511, for example, in the method described above with reference to FIG. Estimate the Cartesian coordinates of the mobile terminal under consideration.

  In step 515, the orthogonal coordinates of the mobile terminal obtained in step 513 are converted into latitude and longitude information.

  In step 517, the call quality determined in step 505 is evaluated. For example, whether the call quality is poor is evaluated by determining whether the FER is greater than 10.

  If FER is greater than 10, in step 519, a symbol indicating call quality is plotted on the map using the latitude and longitude information of the mobile terminal under consideration obtained in step 515. The symbols indicating the call quality may be plotted according to whether or not the call quality is lower than a predetermined value, for example, as described above, or only for a mobile terminal having a poor call quality. Symbols and the like may be plotted.

  Such processing is performed for a large number of mobile terminals using data obtained from the call detail information. This makes it possible to create a map in which position and quality information relating to a large number of mobile terminals is plotted. By referring to such a map, it is possible to know areas where the call quality is poor in the service area of the cellular communication system. Can take necessary measures.

  FIG. 6 is a processing block diagram showing the procedure of the area diagnosis method using such detailed call information from another viewpoint. FIG. 7 is an explanatory diagram showing the contents of each information file and the processing results when such processing is performed. Further, FIGS. 8 and 9 are explanatory views illustrating details of the output result obtained by such processing.

  In block 601 of FIG. 6, the call details of all users are collected as CDL in the data logger of the central exchange 7 (FIG. 1). The data logger is configured as, for example, a UNIX (registered trademark) server. Further, such call detailed information is obtained by collecting various data transmitted from each mobile terminal to the base station at the end of the call, for example, from the base station every predetermined time. This detailed call information includes the station number of each mobile terminal, the station number and phase delay information of the base station that communicates with the mobile terminal, the number of PMRM message transmissions, and the like.

  Next, in block 603, necessary data in the call detail information (CDL) collected by the data logger is downloaded to the local computer 9 (FIG. 1). Then, from the downloaded information, a CDL information file including information as shown in block 701 of FIG. 7 is created. This CDL information file includes, for example, the number of each mobile terminal, the station numbers of three base stations that communicate with the mobile terminal, signal propagation delay time (phase delay) information between these three base stations and the mobile terminal, PMRM message Data indicating the transmission frequency of the message is included.

  In addition, as indicated by block 603 in FIG. 6, the local computer 9 creates a base station (BTS) information file from previously known base station information. This base station information file includes, for example, the station number and position of the necessary base station, that is, latitude and longitude information. A block 703 in FIG. 7 shows a configuration example of such a base station information file.

  Next, as shown in block 605 of FIG. 6, the above-mentioned CAD tool, which is the central part of a program for performing area diagnosis using call detailed information according to the present invention, is executed by the local computer 9. CAD is an abbreviation that means area diagnosis using CDL. The CAD tool executes the processing shown in FIG. 5 using the CDL information file and the BTS information file, calculates the position of each mobile terminal, and estimates call quality, for example, FER. By this processing, latitude / longitude information and call quality information of each mobile terminal are output, for example, in text format. Block 705 in FIG. 7 shows an example of such output data.

  Next, as shown in block 607 of FIG. 6, the output data obtained by the CAD tool, such as latitude, longitude and call quality data for a number of mobile terminals, is mapped onto a map. This mapping can be done using a suitable printer, mapping tool, etc. Block 707 in FIG. 7 shows an example of the mapping result obtained in this way. In the example of FIG. 7, mobile terminals whose call quality is lower than a predetermined value are mapped with × marks, and mobile terminals whose call quality is higher than a predetermined value are mapped with ○ marks. Each base station (BTS) is also shown.

  Next, as shown in block 609 of FIG. 6, mobile terminals with poor internal call quality are extracted, for example, mobile terminals with FER> 10% or Ec / Io <−16 dB, and these mobile terminals are extracted. Plot only the terminal on the map. Block 709 in FIG. 7 shows a map with such a plot. This makes it possible to easily detect an area with poor quality.

  That is, the quality information of all the mobile terminals plotted on the map in block 707 in FIG. 7 is statistically processed to extract, for example, a bad area and plotted on the map as shown in block 709 in FIG. Thus, it is possible to more accurately determine the quality of the parameters in each area.

  Note that the plotting method of the mobile terminal and the parameters used as a reference for plotting, for example, call quality, can be arbitrarily set.

  FIG. 8 and FIG. 9 show examples of maps in which call quality data of each mobile terminal is plotted. FIGS. 8 and 9 show the blocks 707 and 709 in FIG. 7 in an enlarged manner, respectively. FIG. 8 shows an example in which a mobile terminal having a call quality worse than a predetermined value and a mobile terminal having a predetermined value or more are plotted together with crosses and circles, respectively. FIG. 9 is a plot of only mobile terminals whose call quality is lower than a predetermined value.

  Thus, according to the present invention, by plotting parameters such as call quality for a large number of mobile terminals, it is possible to know the distribution in each area such as call quality. Therefore, the call quality of each area can be diagnosed quickly and in real time without using the drive test as in the prior art. Such a call quality plot can be collected simultaneously and continuously over a wide service area, and the temporal and spatial transition of the call quality can be estimated very accurately. As a result, for example, what measures should be taken in an area where the call quality is poor in the cellular communication system can be easily understood, and fine and good service can be provided to the user of the cellular communication system.

  The arrangement plan of each base station of the cellular communication system, the setting of the transmission power of each base station, etc. can be performed extremely accurately. Thereby, the operation of the cellular communication system is also performed accurately, and it becomes possible to provide a more precise and detailed service to the user.

It is a block diagram which shows the schematic structure of the hardware for implementing the area diagnosis method using the call detailed information concerning one Embodiment of this invention. It is explanatory drawing which shows the outline of the area diagnosis result obtained by the system of FIG. It is a schematic explanatory drawing which shows the state which filtered and mapped the area diagnosis result of FIG. 2 on the map. It is explanatory drawing which shows one method of estimating the position of a mobile terminal. It is a flowchart which shows the outline of the process of the area diagnosis method and program which used the detailed call information concerning one Embodiment of this invention. It is a processing block diagram explaining the outline of the process of the area diagnosis method and program using the call detailed information concerning this invention from another viewpoint. It is explanatory drawing which shows an example of the input and output data used in the process of FIG. It is explanatory drawing which shows an example which plotted the output data on the map by the method and program concerning this invention. It is explanatory drawing which shows the other example of the output data plotted on the map with the method and program concerning this invention.

Explanation of symbols

3 base station 5 mobile terminal 7 central switching center 9 local computer 701 call detailed information file 703 base station information file 705 output data 707 mapping result 707 other mapping result

Claims (16)

An area diagnosis method using call detail information in a cellular communication system including a plurality of base stations each capable of communicating with a plurality of mobile terminals, and an exchange connected to the plurality of base stations,
(A) From call detailed information collected from a plurality of mobile terminals via a plurality of base stations in the exchange, call quality of a certain mobile terminal, station number information of a plurality of base stations near the mobile terminal, and the plurality Collecting signal propagation delay time information between the base station and the mobile terminal;
(B) for a plurality of base stations in the vicinity of the mobile terminal, collecting base station information including at least a base station number and base station position information;
(C) A procedure for obtaining the position of the mobile terminal based on station number information and position information of a plurality of base stations in the vicinity of the mobile terminal and signal propagation delay time information between the base stations in the vicinity of the mobile terminal and the mobile terminal ,
(D) a procedure for outputting the location information and call quality information of the mobile terminal in association with each other;
(E) a procedure for performing the procedures (A) to (D) for a plurality of mobile terminals;
An area diagnosis method using detailed call information.   The procedure for determining the position of the mobile terminal is based on the difference in distance between the plurality of base stations near the mobile terminal and the mobile terminal from the signal propagation delay time information between the base stations near the mobile terminal and the mobile terminal. The area diagnosis method using call detailed information according to claim 1, wherein the position of the mobile terminal is obtained using the distance difference.   2. The area diagnosis method using call detailed information according to claim 1, wherein mobile terminals having call quality within a predetermined range are extracted and plotted on a map.   4. The area diagnosis method using call detailed information according to claim 3, wherein mobile terminals having call quality lower than a predetermined value are extracted and plotted on a map.   The area diagnosis method using call detailed information according to claim 1, wherein the base station information is collected from base station information predetermined for the cellular communication system.   The position of the base station in the base station information is represented by the latitude and longitude of the base station, the latitude and longitude are converted into orthogonal coordinates, and the converted orthogonal coordinates and signal propagation delay time information between the base station and the mobile terminal To obtain a distance difference between the base station and the mobile terminal, obtain orthogonal coordinates of the mobile terminal based on the distance difference, and convert the orthogonal coordinates of the mobile terminal to longitude and latitude to obtain position information of the mobile terminal The area diagnosis method using the detailed call information according to claim 1.   The area diagnosis method using call detailed information according to claim 1, wherein the call quality information is a frame error rate or a bit error rate.   2. The area diagnosis method using call detail information according to claim 1, wherein the cellular communication system is a CDMA communication system.   9. The area diagnosis method using call detailed information according to claim 8, wherein the call quality information is obtained from a transmission frequency of a power measurement request message (PMRM).   2. The area diagnosis method using call detail information according to claim 1, wherein the call detail record is transmitted from each mobile terminal to the base station at the end of the call. A program that causes a computer to execute an area diagnosis method using detailed call information in a cellular communication system that includes a plurality of base stations that can communicate with a plurality of mobile terminals, and an exchange connected to the plurality of base stations. And
(A) From call detailed information collected from a plurality of mobile terminals via a plurality of base stations in the exchange, call quality of a certain mobile terminal, station number information of a plurality of base stations near the mobile terminal, and the plurality Collecting signal propagation delay time information between the base station and the mobile terminal;
(B) for a plurality of base stations in the vicinity of the mobile terminal, collecting base station information including at least a base station number and base station position information;
(C) A procedure for obtaining the position of the mobile terminal based on station number information and position information of a plurality of base stations in the vicinity of the mobile terminal and signal propagation delay time information between the base stations in the vicinity of the mobile terminal and the mobile terminal ,
(D) a procedure for outputting the location information and call quality information of the mobile terminal in association with each other;
(E) a procedure for performing the procedures (A) to (D) for a plurality of mobile terminals;
A program that causes a computer to execute.   The procedure for determining the position of the mobile terminal is based on the difference in distance between the plurality of base stations near the mobile terminal and the mobile terminal from the signal propagation delay time information between the base stations near the mobile terminal and the mobile terminal. The program according to claim 11, wherein the position of the mobile terminal is obtained using the distance difference.   The position of the base station in the base station information is represented by the latitude and longitude of the base station, the latitude and longitude are converted into orthogonal coordinates, and the converted orthogonal coordinates and signal propagation delay time information between the base station and the mobile terminal To obtain a distance difference between the base station and the mobile terminal, obtain orthogonal coordinates of the mobile terminal based on the distance difference, and convert the orthogonal coordinates of the mobile terminal to longitude and latitude to obtain position information of the mobile terminal The program according to claim 11. An area diagnostic apparatus using call detail information in a cellular communication system including a plurality of base stations each capable of communicating with a plurality of mobile terminals, and an exchange connected to the plurality of base stations,
(A) From call detailed information collected from a plurality of mobile terminals via a plurality of base stations in the exchange, call quality of a certain mobile terminal, station number information of a plurality of base stations near the mobile terminal, and the plurality Means for collecting signal propagation delay time information between the base station and the mobile terminal;
(B) for a plurality of base stations in the vicinity of the mobile terminal, means for collecting base station information including at least a base station number and base station position information;
(C) Means for determining the position of the mobile terminal based on station number information and position information of a plurality of base stations in the vicinity of the mobile terminal and signal propagation delay time information between the plurality of base stations in the vicinity of the mobile terminal and the mobile terminal ,
(D) means for outputting location information of the mobile terminal and call quality information in association with each other;
(E) With respect to a plurality of mobile terminals, the means (A) to (D) are made to function and the position information and the call quality information are output in association with the plurality of mobile terminals,
An area diagnostic apparatus using detailed call information.   The means for obtaining the position of the mobile terminal is a distance difference between the base stations near the mobile terminal and the mobile terminal based on signal propagation delay time information between the base stations near the mobile terminal and the mobile terminal. 15. The area diagnosis apparatus using call detailed information according to claim 14, wherein the position of the mobile terminal is obtained using the distance difference. The position of the base station in the base station information is represented by the latitude and longitude of the base station, the latitude and longitude are converted into orthogonal coordinates, and the converted orthogonal coordinates and signal propagation delay time information between the base station and the mobile terminal To obtain a distance difference between the base station and the mobile terminal, obtain orthogonal coordinates of the mobile terminal based on the distance difference, and convert the orthogonal coordinates of the mobile terminal to longitude and latitude to obtain position information of the mobile terminal The area diagnosis apparatus using call detail information according to claim 14.

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