JP2001024599A - Channel search control method for evaluating service area, service area evaluation device and service area evaluation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly and efficiently search for a channel to be measured from channels for measurement transmitted from peripheral base stations. SOLUTION: Transmission-reception distances between a mobile measuring vehicle 5 and peripheral base stations 1 to 4 are calculated on the basis of the contents of a base station data base and position measuring information. Consequently, it is grasped in which power range of a base station the vehicle 5 executing mobile measurements is located and in which power range of a base station the vehicle enters after movement a place for switching a measuring channel can be narrowed down and a channel can be efficiently obtained without searching for a channel at a fixed interval differently from a conventional method. Since peripheral base stations 1 to 4 can be also grasped in addition to the base station in the power range, channels can be narrowed down and quick channel search can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel search control method for evaluating a service area in a mobile communication system using a cellular system, a service area evaluation apparatus, and a service area evaluation system.

[0002]

2. Description of the Related Art In order to obtain data for service area evaluation, a mobile measuring vehicle moves propagation characteristics and communication quality characteristics using channels (for example, perch channels) constantly transmitted from a plurality of base stations. When measuring, a mobile measurement vehicle must perform a channel search to detect receivable channels. Receivable channels change during traveling due to the relationship with the surrounding base stations.
For this reason, conventionally, it has been necessary to perform a channel search at certain intervals (for example, time intervals, distance intervals, etc.).

[0003]

However, in the above-described prior art, since the search is performed at fixed time intervals (distance intervals), the channel search is performed in a place where the measurement channel does not change. In some cases, the channel search is performed far from the place where the channel search is to be performed, which is an inefficient control.
If the number of channels to be searched is small, the time required for the channel search does not matter, but if the number of channels increases, the processing time of the channel search cannot be ignored. Since the propagation characteristics and communication quality characteristics cannot be measured during the channel search process, when the number of channels is large, the channel search interval must be set longer or the measurement must be performed in advance by limiting the channels.

[0004] However, when the former channel search interval is set to be long, the channel being measured cannot be received during moving measurement, or cannot be changed at a place where the measurement channel is originally changed. On the other hand, when the measurement is performed with the channel limited, the measurable area is limited.

[0005] As described above, when the number of channels increases, the processing time for searching channels increases, so that there is a disadvantage that detailed measurement cannot be performed or a measurement area is limited.

An object of the present invention is to solve the above-mentioned problems, realize a high-speed and efficient channel search, and achieve a detailed and unlimited measurement area for a service area evaluation. To provide a channel search control method, a service area evaluation device, and a service area evaluation system.

[0007]

According to the present invention, the above objects are achieved by the features set forth in the appended claims.
That is, the present invention is capable of performing an efficient channel search by monitoring neighboring base stations while measuring movement by a movable measuring device, and always performs a channel search at regular time intervals (distance intervals). It is different from the conventional technology.

[0008] The first aspect of the present invention relates to a base station when performing measurement for service area evaluation by a mobile measuring device using a channel which is constantly transmitted from a base station to which a cellular system is applied. A base station to be searched for a channel is determined based on data from a database storing data and a position measurement result of the measuring device from a position measuring unit.

According to a second aspect of the present invention, in the first aspect, the distance between the measuring device and the peripheral base station is determined based on the data from the database and the position measurement result from the position measuring means. Calculating, referring to the calculation result, performing a channel search based on a timing at which a new base station within a preset distance between the measuring device and a peripheral base station is recognized. .

Further, according to the invention of claim 3, in claim 2, only the channel transmitted from a new base station and the channel under measurement within a preset distance between the measuring device and the peripheral base station are set. A channel search is performed as an object.

According to a fourth aspect of the present invention, in the first aspect, the propagation characteristic of a channel transmitted from a peripheral base station is estimated by the measuring device, and a new measurement should be performed with reference to the estimation result. Channel exists (for example,
It is characterized in that a channel search is executed based on the timing at which the reception level is estimated to exceed the user setting value.

According to a fifth aspect of the present invention, in the fourth aspect, a channel search is performed only on a channel newly determined to be measured and a channel under measurement obtained by referring to the estimation result. It is characterized by the following.

Further, according to the present invention, there is provided a service area evaluation apparatus having a movable measurement apparatus for performing measurement for service area evaluation using a channel constantly transmitted from a base station to which a cellular system is applied. A database that stores data on base stations,
Position measuring means for measuring the position of the measuring device, data from the database, based on the position measurement result from the position measuring means, a means for determining a base station to perform a channel search, Features.

According to a seventh aspect of the present invention, in the sixth aspect, the distance between the measuring device and the peripheral base station is determined based on the data from the database and the position measurement result from the position measuring means. A distance calculating means for calculating, and referring to a calculation result from the distance calculating means, a channel based on a timing at which a new base station within a preset distance between the measuring device and a peripheral base station is recognized. Channel search executing means for executing a search.

In the invention according to claim 8, the channel search execution means according to claim 7, wherein the channel transmitted from a new base station within a preset distance between the measuring device and a peripheral base station. And performing a channel search only for the channel under measurement.

In a ninth aspect of the present invention, in the sixth aspect, a propagation characteristic estimating means for estimating a propagation characteristic of a channel transmitted from a peripheral base station and an estimation result from the propagation characteristic estimating means are referred to. Channel search execution means for executing a channel search based on the timing at which it is recognized that a channel to be newly measured exists.

According to a tenth aspect of the present invention, in the ninth aspect, the channel search executing means selects only a channel determined to be newly measured and a channel under measurement obtained by referring to the estimation result. A channel search is performed as an object.

Further, the invention of claim 11 is characterized by a service area evaluation system including one or more base stations to which the cellular system is applied and the service area evaluation device according to any one of claims 6 to 10.

According to the present invention having the above characteristics, it is possible to calculate the transmission / reception distance between the movable measurement device and the peripheral base station. For this reason, it is possible to know which base station is within the range of the measuring device during the mobile measurement, and which station is the base station that will be in the next range of power at the destination, and to switch the measurement channel. Is limited, and there is no need to perform a channel search at regular intervals as in the related art, which is efficient. Also, in addition to base stations within range,
Since the surrounding base stations can also be grasped, channels to be searched in the channel search can be limited, and high-speed channel search can be realized. On the other hand, by estimating the propagation characteristics of the channel transmitted from each base station in addition to the database relating to the base station, it is possible to select a channel search location and a candidate for a channel to be searched in more detail, thereby achieving high speed and high speed. An accurate channel search can be efficiently realized.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 is a conceptual diagram of the service area evaluation system of the present invention. In FIG. 1, reference numerals 1 to 4 denote base stations installed in a service area, and reference numerals 6 to 9 denote base stations 1 to 4, respectively.
This is a measurement channel that is constantly transmitted from. Reference numeral 5 denotes a mobile measurement vehicle, on which a service area evaluation device described later is mounted. The service area evaluation system of the present invention includes an evaluation device and one or more base stations.

When measuring the propagation characteristics and communication quality characteristics at the mobile measurement vehicle 5 (receiving station) using the measurement channel, the mobile measurement vehicle must first search for a measurable channel. The channel to be measured is determined from the search result, and measurement of the propagation characteristics and the like of the channel is started.

However, since the mobile measurement vehicle measures while moving, the channel to be measured (measurable) changes during traveling. For example, in FIG.
The reception levels of channels 6 and 7 transmitted from the base station 3 are high, but those channels are measured. In the course of traveling, the reception level of channel 8 transmitted from the base station 3 increases, and the channel 8 is added to the measurement channel. When the vehicle further travels, the reception level of the channel 6 transmitted from the base station 1 becomes weaker, and instead the reception level of the channel 9 transmitted from the base station 4 becomes stronger. Therefore, the channel 6 is deleted from the measurement target channel, Channel 9 is added to the channel to be measured.

Therefore, in the mobile measuring vehicle, a channel search is performed again at a certain timing, and a channel to be measured is searched again. In the present invention, the timing of the channel search is controlled using the propagation estimation system in addition to the base station database or the base station database, and the channel search is performed only at the most appropriate place.

FIG. 2 is a diagram showing an example of the service area evaluation device of the present invention. In FIG. 2, reference numeral 20 denotes a control device, which controls the entire evaluation apparatus. Also, the control device 2
0 is a function for determining a base station to be subjected to a channel search, which will be described later in detail, a function for calculating a transmission / reception distance, a propagation estimation function,
It has a data processing function. 21 is a monitor device for acquired data, 22 is a database for accumulating acquired data,
23 is a position measuring device for acquiring position data of a mobile measuring vehicle using GPS, 24 is a measuring device having communication means (including an antenna) with a base station, and a channel search execution function; A function of receiving a measurement channel and measuring a propagation characteristic and a communication quality characteristic. 2
Reference numeral 5 denotes a base station database in which information on base stations (details will be described later) is stored, and reference numeral 26 denotes a map database displayed on a monitor together with the base station position and the position of the mobile measurement vehicle. Each database can be realized by a hard disk device.

FIG. 3 is a channel search control flow executed by the control device 20 of FIG.

First, at the same time as the start of the measurement, the position information of the mobile measuring vehicle is obtained from the position measuring device (S1). When the position is equal to the calculation target point set in advance by the user (S2), the calculation is started (S3). In the calculation, first, the position information of the base station in the service area is obtained from the base station database, and the distance between each base station and the mobile measurement vehicle (based on the position information and the position information of the mobile measurement vehicle from the position measurement device) ( Calculate the transmission / reception distance).

Subsequently, the base station refers to the distance threshold value of the channel search target base station set in advance by the user (S4), and selects a base station within the threshold value from the obtained transmission / reception distance (S5). . Subsequently, in S5, it is determined whether or not to perform propagation estimation. If propagation estimation is not to be performed, the selected base station is compared with the base station selected at the previous calculation point (S10), and in S11. If both are determined to be the same, the process returns to S1, and it is determined that they are not the same. If a new base station is added (or if the number of stations is changed beyond a certain fixed number), the selected base station is determined. The frequency (spreading code in the case of the CDMA system) information of the channel transmitted from the station is acquired from the base station database (S12), and the information is sent to the measuring device together with the channel search request (S1).
3) The measuring device performs a channel search based on the information, and measures the propagation characteristics and the communication quality characteristics using the determined channel. The above procedure is performed until the measurement is completed (S14).

The above is the description of the channel search control using only the base station database. The case where the channel search control using the propagation estimation result in addition to the base station database in S6 will be described below. In this case, S7
Then, information necessary for propagation estimation such as the base station antenna height and transmission power for the selected base station is obtained from the base station database, and the propagation characteristics of the channel transmitted from each base station at the calculation target point (for example, the measurement location Estimating the reception level and delay profile at the same time. Referring to the obtained estimation result and the propagation characteristic threshold condition set by the user in advance (S8), only the base station within the threshold is newly selected as the selected base station (S9), and the process proceeds to S10. The processing is performed in the same manner as when no estimation is performed.

Although the present embodiment has shown a method of performing channel search control by calculating the transmission / reception distance or propagation characteristic in real time, a measurement course is determined in advance, and the transmission / reception distance or propagation at each location is determined as preprocessing. It is also possible to perform channel search control by referring to the result in the actual measurement after calculating the characteristics.

[0030]

As described above, according to the present invention,
By using a database relating to a base station for a movable measurement device and further using a propagation estimation result as needed, it is possible to limit a place where a channel search is performed and a channel to be searched, thereby achieving a high-speed and efficient channel search. Can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of the present system.

FIG. 2 is a diagram showing an example of a service area evaluation device of the present invention.

FIG. 3 is a flowchart of a channel search control operation of the present invention.

[Explanation of symbols]

 1-4 base station 6-9 measurement channel 20 controller 21 monitor 22 acquired data storage database 23 position measuring device 24 measuring device 25 base station database 26 map database

Continuing from the front page (72) Inventor Shinichi Mori 2-1-1, Toranomon, Minato-ku, Tokyo NTT Mobile Communications Network Co., Ltd. F-term (reference) 5K022 AA10 AA21 EE02 EE11 EE31 5K042 AA06 CA02 CA11 CA12 CA23 DA11 EA01 FA15 GA01 JA02 LA06 MA03 MA04 5K067 AA22 BB02 DD34 EE02 EE10 EE16 EE64 HH23 JJ13 JJ34 JJ51 KK15 LL01 LL11

Claims (11)

[Claims] 1. A database storing data relating to a base station when performing measurement for evaluating a service area by a mobile measuring device using a channel which is constantly transmitted from a base station to which a cellular system is applied. A channel search control method for service area evaluation, wherein a base station to be subjected to a channel search is determined on the basis of data from the base station and a position measurement result of the measuring device from a position measuring unit. 2. The distance according to claim 1, wherein a distance between the measuring device and a peripheral base station is calculated based on data from the database and a position measurement result from the position measuring means. Referring to, for a service area evaluation characterized by performing a channel search based on the timing at which a new base station within the preset distance between the measuring device and the peripheral base station is recognized Channel search control method. 3. The channel search according to claim 2, wherein only a channel transmitted from a new base station and a channel under measurement within a preset distance between the measuring device and a peripheral base station are targeted. A channel search control method for service area evaluation. 4. The method according to claim 1, wherein the measurement device estimates propagation characteristics of a channel transmitted from a peripheral base station, and refers to the estimation result to recognize that a channel to be newly measured exists. A channel search control method for service area evaluation, characterized in that a channel search is executed based on the determined timing. 5. The service according to claim 4, wherein a channel search is executed only for a channel newly determined to be measured and a channel under measurement obtained by referring to the estimation result. Channel search control method for area evaluation. 6. A service area evaluation device having a movable measurement device for performing measurement for service area evaluation using a channel constantly transmitted from a base station to which a cellular system is applied, comprising: A base station to perform a channel search based on data from the database and a position measurement result from the position measurement unit. A service area evaluation device comprising: 7. The distance calculation unit according to claim 6, wherein a distance between the measurement device and a peripheral base station is calculated based on data from the database and a position measurement result from the position measurement unit. A channel search for performing a channel search based on a timing at which a new base station within a preset distance between the measuring device and a peripheral base station is recognized, with reference to a calculation result from the distance calculating means. A service area evaluation device, comprising: an execution unit. 8. The channel search execution unit according to claim 7, wherein the channel search execution unit is configured to perform only a channel transmitted from a new base station and a channel under measurement within a preset distance between the measurement device and a peripheral base station. A service area evaluation device for executing a channel search for a service. 9. A transmission characteristic estimating means for estimating a propagation characteristic of a channel transmitted from a peripheral base station, and a new measurement is to be performed by referring to an estimation result from the propagation characteristic estimating means. A channel search execution unit that executes a channel search based on the timing when it is recognized that a channel exists. 10. The channel search execution unit according to claim 9, wherein the channel search execution unit executes a channel search only for a channel newly determined to be measured and a channel under measurement obtained by referring to the estimation result. A service area evaluation device characterized in that: 11. A service area evaluation system, comprising one or more base stations to which a cellular system is applied, and the service area evaluation device according to any one of claims 6 to 10.