Area design device, and area design method

The present invention relates to an area design device and an area design method in wireless communication, and more particularly to an area design device and an area design method using a radio wave propagation simulator.

In wireless communication systems, area designs such as installation of new base stations and adjustment of wireless parameters (antenna direction, tilt angle, antenna power, etc.) are performed for the purpose of maintaining or improving communication quality.

As means to support these area designs, radio wave quality (Received Signal Code Power (RSCP)) in the target area, energy to in-band received power density ratio per desired wave chip (Ec / N0) ) Etc.) is used in a radio wave propagation simulator that estimates the distribution.

By using the radio wave propagation simulator, it is possible to estimate the radio wave quality distribution after area design without using actual measured values, or to estimate the area quality from a limited number of measurement points. It will be possible to proceed with the examination smoothly and efficiently.

In area design using a radio wave propagation simulator, a macro evaluation index for the entire area, for example, the area coverage ratio, which is the ratio of the area of the serviceable area (cover area) to the area of the entire area to be designed, is used. It is common to evaluate the effectiveness of area design.

For example, as an example of related technology, Patent Document 1 is formulated as an optimization problem by combining appropriate arrangements of base stations, and an evaluation function is defined using the number of base stations and the area coverage rate to minimize the number of base stations. A technique for obtaining a predetermined area coverage rate by number is described.

Further, as another example of the related technology, Patent Document 2 evaluates both the coverage area and the interference by using the measured value of the communication quality at the base station as a method of designing the area without using the radio wave propagation simulator. Techniques for optimizing the tilt angle of the antenna are described.

Further, as another example of the related technology, in Patent Document 3, the amount of change in radio wave quality before and after area design is obtained by a radio wave propagation simulator, and the amount of change is added to the radio wave quality measurement value before area design. By doing so, the technology for estimating the radio wave quality after area design is described.

<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2001-285923</text></patcit><patcit num="2"><text>Special Table 2001-518767</text></patcit><patcit num="3"><text>Japanese Patent Application Laid-Open No. 2005-223732</text></patcit>

<p> However, in the related technology (see Patent Documents 1 and 2) in which the area is designed based on the above-mentioned area coverage rate and the measured value of the communication quality at the base station, a specific local area (for example, a specific building, area, etc.) There is a problem that it is difficult to design an area after appropriately considering the deterioration of radio wave quality that occurs in the above.</p><p> That is, although it is possible to evaluate the improvement and deterioration of the radio wave quality in the entire area or in each base station, the radio wave quality is improved or deteriorated at any position in the area and with a certain degree of area spread by the area design. It is difficult to design the area after quantitatively grasping whether or not to do so.</p><p> The related technology described in Patent Document 3 described above has the same problems as the related technology described in Patent Documents 1 and 2. That is, the related technology described in Patent Document 3 aims to improve the accuracy of estimating the radio wave quality in the entire area, and does not disclose the evaluation method of local quality deterioration resulting from the area design.</p><p> Therefore, in the above-mentioned related technology, there may be a case where the area that could be serviced before the area design becomes unserviceable after the area design, and as a result of the area design, it is important that people such as stations and department stores are highly public and concentrated. It may deteriorate the radio wave quality in various places and cause dissatisfaction of many service users.</p><p> Therefore, it is possible to design an area after quantitatively grasping at what position in the area and to what extent the radio wave quality is improved or deteriorated by the area design. The purpose is to provide an area design device and an area design method.</p>

<p> In order to solve the above-mentioned problems, the area design device according to the present invention acquires the radio wave quality distribution before and after the area design, and extracts the area where the radio wave quality is improved by the area design, and the area design. Includes a deteriorated area extraction unit that acquires the radio wave quality distribution before and after the area design and extracts the area where the radio wave quality has deteriorated due to the area design, and a control unit that controls the improved area extraction unit and the deteriorated area extraction unit. It is characterized by that.</p><p> Further, the area design method according to the present invention includes an improvement area extraction step of acquiring the radio wave quality distribution before and after the area design and extracting the area where the radio wave quality is improved by the area design, and before and after the area design. It is characterized by including a deteriorated area extraction step of acquiring the radio wave quality distribution of the above and extracting the area where the radio wave quality has deteriorated by the area design.</p><p> Further, the program according to the present invention has an improvement area extraction step of acquiring the radio wave quality distribution before and after the area design and extracting the area where the radio wave quality is improved by the area design, and the area design before and the area design. It is characterized in that it is a program for acquiring a later radio wave quality distribution and executing a deteriorated area extraction step of extracting a region where the radio wave quality has deteriorated by area design.</p>

<p> According to the present invention, it is possible to perform area design after quantitatively grasping at what position in the area and to what extent the radio wave quality is improved or deteriorated by the area design. A design device and an area design method can be obtained.</p>

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. (First Embodiment)

FIG. 1 is a block diagram of the first embodiment of the present invention.

With reference to the figure, the area design device 1 acquires the radio wave quality distribution before and after the area design, and extracts the area where the radio wave quality is improved by the area design. The improvement area extraction unit 11 and the area before and after the area design. Includes a deteriorated area extraction unit 12 that acquires the radio wave quality distribution after design and extracts the area where the radio wave quality has deteriorated due to area design, and a control unit 13 that controls the improved area extraction unit 11 and the deteriorated area extraction unit 12. It is composed. A detailed description of the improved region extraction unit 11 and the deteriorated region extraction unit 12 will be described later together with FIG.

Next, with reference to FIG. 2, the operation of the first embodiment for carrying out the present invention will be described. FIG. 2 is a flowchart showing an example of the operation of the first embodiment of the present invention.

The control unit 13 controls the improvement area extraction unit 11 and the deterioration area extraction unit 12, and causes the improvement area extraction unit 11 and the deterioration area extraction unit 12 to perform the following processing.

With reference to the figure, the improvement area extraction unit 11 acquires the radio wave quality distribution before and after the area design, and extracts the area where the radio wave quality is improved by the area design (step S1).

Next, the deteriorated area extraction unit 12 acquires the radio wave quality distribution before and after the area design, and extracts the area where the radio wave quality has deteriorated due to the area design (step S2).

As described above, according to the first embodiment, both the area where the radio wave quality is improved and the area where the radio wave quality is deteriorated are separately extracted by the area design. It is possible to design the area after quantitatively grasping whether the radio wave quality is improved or deteriorated with the spread of the area. (Second embodiment)

FIG. 3 is a block diagram of a second embodiment of the present invention. The second embodiment relates to another example of the configuration of the area design device. In FIG. 3, the same components as those in FIG. 1 are numbered the same.

Referring to FIG. 3, the area design device 1 includes an area design instruction unit 14, a radio wave propagation estimation unit 15, a geographic information storage unit 16, a radio wave quality storage unit 17, an improvement area extraction unit 11, and a deteriorated area extraction unit. It is composed of a unit 12, an evaluation unit 18, a display unit 19, a control unit 13, and a program storage unit 20.

The area design instruction unit 14 is an input means for installing a new base station, adjusting radio parameters, instructing a base station to execute radio wave propagation estimation, and inputting from an input device such as a keyboard or a mouse. It receives a file or the like containing the information stored in a storage device such as a hard disk and gives it to the radio wave propagation estimation unit 15.

The radio wave propagation estimation unit 15 is a means for holding base station information such as the position of the base station and radio parameters and executing radio wave propagation estimation in a target area.

When the radio wave propagation estimation unit 15 receives an instruction from the area design instruction unit 14 of the base station to execute the radio wave propagation estimation, the radio wave propagation estimation unit 15 acquires the geographic information (topography, buildings, etc.) around the base station from the geographic information storage unit 16. , Performs radio wave propagation estimation based on the acquired geographic information and the retained base station information.

Further, the radio wave propagation estimation unit 15 can also receive instructions such as correction or addition of base station information given by the area design instruction unit 14 and execute radio wave propagation estimation based on the information.

The information to be estimated is the radio wave quality such as desired wave received power (RSCP) and energy to in-band received power density ratio (Ec / N0) per desired wave chip for each radio cell at any point in the area. Is included.

The radio wave quality estimated by the radio wave propagation estimation unit 15 is stored by the radio wave quality storage unit 17, and can be output to a display unit 19 such as a display for display on the screen.

Radio wave propagation estimation methods include statistical methods such as the Hata-Okumura model, which statistically models the propagation curve representing radio wave propagation characteristics based on actual radio wave quality measurements, and geometrical optics methods. A ray tracing method or the like that predicts the propagation characteristics of radio waves can be used. Since the specific method of radio wave propagation estimation is not directly related to the present invention, detailed description thereof will be omitted.

The geographic information storage unit 16 is a means for storing information such as topography, buildings, roads, railroads, rivers, population density, building density, and building type in association with location information (for example, latitude and longitude). For these geographic information, electronic maps provided by the Geospatial Information Authority of Japan and map makers and statistical survey results (regional mesh statistics) such as census can be used. Since the specific data format and the like are not directly related to the present invention, detailed description thereof will be omitted.

The geographic information stored by the geographic information storage unit 16 is sent to the radio wave propagation estimation unit 15, and can be used for executing the radio wave propagation estimation and displaying the result by the display unit 19.

The radio wave quality storage unit 17 is a means for storing the radio wave quality (radio wave quality estimated value) estimated by the radio wave propagation estimation unit 15.

FIG. 4 shows an example of a holding mode of the radio wave quality estimated value stored by the radio wave quality storage unit 17. As shown in FIG. 4, the radio wave quality storage unit 17 receives position information, the best server, desired wave received power (RSCP), and energy vs. in-band reception per desired wave chip for each of before and after area design. The power density ratio (Ec / N0) is stored.

The position information in FIG. 4 is information for identifying a position in a target area, and XY coordinates, latitude / longitude, serial numbers, and the like can be used. In addition, the best server indicates the identifier of the radio cell having the highest RSCP among the radio waves for each radio cell received at the position.

Returning to FIG. 3, the improvement area extraction unit 11 determines the area (quality improvement area) in which the radio wave quality estimated value is improved by the area design from the radio wave quality estimates before and after the area design stored in the radio wave quality storage unit 17. ) Is a means to extract.

Whether or not the radio wave quality estimated value is improved can be determined by obtaining the difference between the radio wave quality estimated value before and after the area design in which the position information is the same.

For example, in the case of FIG. 4, the position where the desired wave received power or the energy-to-band received power density ratio per desired wave chip becomes a higher value after the area design than before the area design may be extracted.

In addition, since a slight change in radio wave quality often does not make much sense when evaluating the entire area quality, another method can be used as a method for extracting the quality improvement area.

As an example, a threshold value for determining service availability may be set for the radio wave quality estimated value, and only an area that is equal to or less than the threshold value before the area design and equal to or more than the threshold value after the area design may be extracted. At this time, by setting the threshold value of the desired wave reception power to -110 dBm, it is possible to extract only the positions where the service is not possible before the area design and the service is possible after the area design.

As another example, a predetermined threshold value may be set for the amount of change in the estimated radio wave quality value, and only the positions where the improvement of the threshold value or more is obtained by the area design may be extracted. If the threshold value for the amount of change in the desired wave reception power is set to 10 dB, the area where the change is 10 dB or less can be ignored, and only the area where the desired wave reception power is improved by 10 dB or more after the area design can be extracted.

The quality improvement area extracted by the improvement area extraction unit 11 is sent to the evaluation unit 18 to evaluate the effectiveness of the area design. It is also possible to output to the display unit 19 in order to confirm the position of the extracted area on the map.

The deteriorated area extraction unit 12 is a means for extracting an area (quality deteriorated area) in which the radio wave quality estimated value is deteriorated by the area design from the radio wave quality estimated values before and after the area design stored in the radio wave quality storage unit 17. Is.

Whether or not the radio wave quality estimated value has deteriorated can be determined by obtaining the difference between the radio wave quality estimated value before and after the area design in which the position information is the same. For example, in the case of FIG. 4, it is sufficient to extract the position where the desired wave received power or the energy-to-band received power density ratio per desired wave chip becomes a value lower than that before the area design after the area design.

As with the extraction of quality improvement areas, slight changes in radio wave quality often do not make much sense when evaluating the overall area quality, so other methods are used to extract quality deterioration areas. You can also take it.

The quality deteriorated region extracted by the deteriorated region extraction unit 12 is sent to the evaluation unit 18 to evaluate the effectiveness of the area design. It is also possible to output to the display unit 19 in order to confirm the position of the extracted area on the map.

The evaluation unit 18 is a means for evaluating the effectiveness of the area design based on the quality improvement area extracted by the improvement area extraction unit 11 and the quality deterioration area extracted by the deterioration area extraction unit 12.

The evaluation result of the area design by the evaluation unit 18 is output to the display unit 19 and can be confirmed by a display or the like. The specific evaluation method in the evaluation unit 18 will be described later.

The display unit 19 is the estimation result of the radio wave quality by the radio wave propagation estimation unit 15, the quality improvement area extracted by the improvement area extraction unit 11, the quality deterioration area extracted by the deterioration area extraction unit 12, and the area design by the evaluation unit 18. It is a means for receiving evaluation results, etc. and displaying them using a display means such as a display.

FIG. 5 is an example of the screen of the evaluation result of the area design displayed by the display unit 19.

Referring to FIG. 5, the radio wave quality distribution 101 before the area design is displayed on the upper left side of the screen 2, the radio wave quality distribution 102 after the area design is displayed on the upper right side of the screen 2, and the radio waves before and after the area design are displayed on the lower left side of the screen 2. The quality improvement area and the quality deterioration area 103 obtained based on the quality distribution are shown, and the area design evaluation result 104 is shown on the lower right side of the screen 2.

Further, the description 105 of the explanation of the above areas 101 to 103 is made below the evaluation result 104 on the screen 2.

That is, with reference to the area 103, the serviceable area, the quality improvement area, and the quality deterioration area are displayed separately and on the same screen.

A program to be described later is stored in the program storage unit 20.

The control unit 13 controls the above-mentioned parts 11, 12, 14 to 20.

FIG. 6 is a flowchart showing an example of the operation of the second embodiment of the present invention. Next, the operation of the second embodiment will be described. The following processing is executed by the control unit 13 controlling the above-mentioned parts 11, 12, 14 to 20.

First, when the area (base station) for area design is designated by the area design instruction unit 14 (step S11), the radio wave propagation estimation unit 15 executes radio wave propagation estimation for the specified area (step S12).

Next, based on the result of radio wave propagation estimation in step S12, the area design instruction unit 14 performs area design such as installation of a new base station and adjustment of radio parameters, and the base station information after the area design is performed by the radio wave propagation estimation unit 15. Is entered (step S13).

The radio wave propagation estimation unit 15 executes radio wave propagation estimation again based on the given base station information (step S14), and determines whether or not the predetermined area coverage rate is satisfied (step S15).

For example, whether or not the area coverage rate is 95% or more can be a determination condition. If this determination condition is not satisfied (in the case of no in step S15), the area design in step S13 is performed again.

On the other hand, when the determination condition of step S15 is satisfied (when yes in step S15), the improvement area extraction unit 11 acquires the radio wave quality estimates before and after the area design from the radio wave quality storage unit 17. , Extract the area where the radio wave quality estimate is improved after the area design (step S16).

Similarly, the deteriorated region extraction unit 12 acquires the radio wave quality estimates before and after the area design from the radio wave quality storage unit 17, and extracts the regions where the radio wave quality estimates have deteriorated after the area design (step S17). ..

Of course, the quality improvement area extraction process (step S16) and the quality deterioration area extraction process (step S17) may be executed in a different order.

Next, the evaluation unit 18 evaluates the effectiveness of the area design based on the quality improvement area extracted by the improvement area extraction unit 11 and the quality deterioration area extracted by the deterioration area extraction unit 12 (step S18).

The evaluation result here is displayed on the screen by the display unit 19, and if the predetermined condition is satisfied (in the case of yes in step S19), the area design is completed, and if the condition is not satisfied (in step S19). (If no), redesign the area in step S13.

For example, an evaluation function having a positive correlation with the area of the quality improvement area and a negative correlation with the area of the quality deterioration area is defined, and it is a determination condition of step S19 that the evaluation value is equal to or more than a predetermined value. Can be done.

Further, a cost function having a negative correlation with the area of the quality improvement region and a positive correlation with the area of the quality deterioration region may be defined, and it may be a determination condition in step S19 that the evaluation value is equal to or less than a predetermined value. ..

Next, a specific example of the evaluation method of the area design will be described.

First, the improvement area extraction unit 11 extracts the area in which the desired wave reception power is improved by the area design and the service is not possible before the area design and can be serviced after the area design as the quality improvement area (step S16).

Next, the deteriorated area extraction unit 12 extracts an area in which the desired wave reception power is deteriorated by the area design and can be serviced before the area design but cannot be serviced after the area design as a quality deteriorated area (step S17).

For example, if the desired wave reception power is -110 dBm or more, it is judged that service is possible, and if it is less than -110 dBm, it is judged that service is not possible. In the evaluation function f, the area of the extracted quality improvement area is s1, the area of the quality deterioration area is s2, the evaluation value is z, and z = f (s1, s2) = s1-k * s2 ... (1) And so on.

Here, k is a constant that defines how much penalty is imposed on the area of the quality deterioration region.

When k = 0, the quality deterioration area is ignored, and the area design is evaluated only from the area of the quality improvement area.

When k = 1, the area design is evaluated as a substantially expanded area of the service area obtained by subtracting the area of the quality deterioration area from the area of the quality improvement area.

For example, when it is desired to keep the area of the quality improvement region 5 times or more the area of the quality deterioration region, it is sufficient to set k = 5 and set the evaluation value z to be 0 or more as the determination condition in step S19.

Further, when the quality improvement area and the quality deterioration area are extracted by the improvement area extraction unit 11 and the deterioration area extraction unit 12, a plurality of radio wave quality indicators (for example, desired wave received power and energy vs. band per desired wave chip) are used. (Internal received power density ratio) may be considered at the same time.

Specifically, the quality improvement area extraction process (step S16) and the quality deterioration area extraction process (step S17) can be operated as follows.

First, at least one of the desired wave received power or the energy to in-band received power density ratio per desired wave chip is equal to or less than a predetermined threshold value before the area design, and the desired wave received power and the desired wave 1 after the area design. The region where the energy-to-band received power density ratio per chip is both equal to or higher than a predetermined threshold is extracted as the quality improvement region (step S16).

Next, before the area design, the desired wave received power and the energy-to-band received power density ratio per desired wave chip are both equal to or higher than a predetermined threshold value, and after the area design, the desired wave received power or the desired wave per chip is used. A region in which at least one of the energy-to-band received power density ratio is equal to or lower than a predetermined threshold is extracted as a quality deterioration region (step S17).

For example, -110 dBm can be used as the desired wave reception power, and -20 dBm can be used as the predetermined threshold value in the case of the energy to in-band received power density ratio per desired wave chip.

As described above, according to the second embodiment, the area where the radio wave quality estimated by the radio wave propagation estimation unit 15 is improved by the area design and the area where the radio wave quality is deteriorated are improved by the improvement area extraction unit 11 and the deterioration area extraction unit. Each of them is obtained by 12, and the area design is evaluated by the evaluation unit 18 in consideration of the position and area of the area. Therefore, it is possible to quantitatively grasp where and how much area the radio wave quality estimate has improved or deteriorated by the area design, and the area that could be serviced in the past cannot be newly serviced by the area design. It is possible to realize an area design that minimizes negative effects such as becoming. (Third embodiment)

Next, a third embodiment for carrying out the present invention will be described. The third embodiment is a modification of the operation of the second embodiment. FIG. 7 shows a flowchart showing an example of the operation of the third embodiment of the present invention.

The basic configuration of the third embodiment of the present invention is the same as that of the second embodiment, but when the evaluation unit 18 evaluates the area design, the quality improvement area and the quality deterioration area are set. The included geographic information can be considered, such as the number of service subscribers, population density, building density, number of public facilities (departments, stations, parks, etc.), pre-specified important points, and so on.

An example of the operation of the area design device 1 in the third embodiment will be described with reference to FIG. 7. In FIG. 7, the same symbols are added to the operations similar to those in the second embodiment (see FIG. 6), and detailed description thereof will be omitted. The following processing is executed by the control unit 13 controlling the above-mentioned parts 11, 12, 14 to 20.

In the third embodiment, the evaluation unit 18 acquires the geographic information of the quality improvement area from the geographic information storage unit 16 (step S21), and the geographic information storage unit 16 obtains the geographic information of the quality deterioration area. The point to be acquired (step S22), the point to evaluate the area design based on the area and geographic information of the quality improvement area and the area and geographic information of the quality deterioration area (step S23), the point of area design It differs from the second embodiment in that the above geographic information is used for the evaluation determination (step S24).

Next, a specific example of the operation of the evaluation unit 18 in the third embodiment will be described.

First, the population density and the number of public facilities in the quality improvement area are obtained from the geographic information storage unit 16.

Next, the population density and the number of public facilities in the quality deterioration area are obtained from the geographic information storage unit 16.

The evaluation function f uses the area of the quality improvement area (s1) and the population density (p1) and the area of the quality deterioration area (s2) and the population density (p2). z = f (s1, p1, s2, p2) = s1 * p1-k * s2 * p2 (2) And so on.

The meaning of the constant k here is the same as that of the fourth embodiment, but in equation (2), the area design is evaluated by the estimated population in the area calculated by multiplying the area by the population density instead of the area. Will be done.

Further, in addition to the above-mentioned restriction on the evaluation value z, the number of public facilities included in the quality deterioration area can be added to the judgment condition of the evaluation of the area design.

In addition, important points in the area (for example, a specific building, area, etc.) are specified in advance by the area design instruction unit 14, and it is determined whether or not the important points are included in the quality improvement area or the quality deterioration area. , The determination result can be used as an evaluation function or displayed by the display unit 19.

FIG. 8 shows an example of the screen of the evaluation result of the area design displayed by the display unit 19.

Referring to FIG. 8, the information 201 in which the base station, the important point, the quality improvement area and the quality deterioration area are superimposed on the map of the area is displayed on the upper left side of the screen 3, and the quality improvement area is displayed on the upper right side of the screen 3. For each of the quality deterioration areas, the area design evaluation result 202 such as area, population density, estimated population, number of public facilities, and whether or not important points are included is displayed.

Further, the description 203 of the explanation of the information 201 is made on the lower left side of the screen 3.

As described above, according to the third embodiment, the area is designed in consideration of the geographical information included in the quality improvement area and the quality deterioration area and the important points specified in advance, so that the station, department store, etc. It is possible to design an area that is public and prevents deterioration of radio wave quality in important areas where people are likely to concentrate.

The area design device 1 shown in FIG. 3 can be configured by hardware, software, or a combination thereof. (Fourth Embodiment)

The fourth embodiment relates to an example of a program of the area design method in the area design device 1.

Referring to FIG. 3, the area design device 1 includes the program storage unit 20. The program storage unit 20 stores the programs of the area design method shown in the flowcharts in FIGS. 2, 6 and 7.

The control unit 13 of the area design device 1 reads the program from the program storage unit 20 and controls each part 11, 12, 14 to 20 according to the program. Since the content of the control has already been described, the description here will be omitted.

As described above, according to the fourth embodiment, both the area where the radio wave quality is improved and the area where the radio wave quality is deteriorated are separately extracted by the area design. A program of an area design method capable of performing an area design after quantitatively grasping whether the radio wave quality is improved or deteriorated with an area spread of the above can be obtained.

It is clear from the above description that the present invention can be similarly used not only for mobile communication but also as an area design device and area design method for fixed wireless communication such as wireless LAN and WiMax.

<figref num="1">It is a block diagram of the 1st Embodiment of this invention.</figref><figref num="2">It is a flowchart which shows an example of the operation of the 1st Embodiment of this invention.</figref><figref num="3">It is a block diagram of the 2nd Embodiment of this invention.</figref><figref num="4">It is a figure which shows an example of the holding form of the radio wave quality estimate value stored by the radio wave quality storage unit 17.</figref><figref num="5">It is a figure which shows an example of the evaluation result of the area design displayed by the display part 19.</figref><figref num="6">It is a flowchart which shows an example of the operation of the 2nd Embodiment of this invention.</figref><figref num="7">It is a flowchart which shows an example of the operation of the 3rd Embodiment of this invention.</figref><figref num="8">It is a figure which shows an example of the evaluation result of the area design displayed by the display part 19.</figref>

Code description

1 Area design equipment A few screens 11 Improvement area extraction section 12 Deteriorated area extraction section 13 Control unit 14 Area design instruction unit 15 Radio wave propagation estimation unit 16 Geographic Information Storage Department 17 Radio quality storage unit 18 Evaluation Department 19 Display 20 Program storage 103,201 Quality improvement area and quality deterioration area 104,202 Area design evaluation results 105,203 Description of display description