JP2011223398A - Radio base station and method of detecting surrounding environmental changes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect changes of a surrounding environment of a radio base station properly.SOLUTION: A radio base station 100 according to an embodiment of the invention takes an image, setting the entire circumference of an azimuth angle of 0°C to 360°C around the radio base station 100 as a photographic range, obtains distance information indicating a distance to an object based on the image data. In addition, the radio base station 100 detects changes of the surrounding environment of the radio base station 100, when two pieces of distance information acquired for the same azimuth angle with different timing are different.

Description

  The present invention relates to a radio base station constituting a radio communication system and a surrounding environment change detection method in the radio base station.

  After the wireless base stations that make up the wireless communication system are installed, the surrounding environment of the wireless base stations may change due to the construction of the building, etc., or the installation status of the surrounding wireless base stations may be changed. There are cases where it is necessary to update the base station configuration information such as the set transmission power of the radio base station to optimize the communication area.

  Conventionally, optimization of a communication area by updating base station configuration information includes area survey by an operator, complaint from a user, abnormality detection using a dedicated monitoring device (see, for example, Patent Document 1 and Patent Document 2), Anomaly detection based on call processing and signal processing statistics in a radio base station (for example, see Patent Document 3) is used as a trigger.

JP-A-5-83157 JP-A-11-136745 JP 2005-64963 A

  However, optimization of a communication area based on an area survey by an operator requires a lot of human resources and work time, and the communication area cannot be quickly optimized. Further, in the area survey by the worker, an error is likely to occur because a change in the environment around the radio base station is judged by visual observation.

  Further, in the case of optimizing the communication area based on the complaint by the user, it becomes an after-the-fact measure, so the communication area cannot be optimized quickly. In addition, the optimization of the communication area based on the abnormality detection based on call processing and signal processing statistics in the radio base station does not directly represent a change in the environment around the radio base station. It is necessary to investigate whether it is due to a change in the surrounding environment or other factors, and a countermeasure cannot be determined quickly.

  In view of the above problems, an object of the present invention is to provide a radio base station and a surrounding environment change detection method that appropriately detect a change in the environment around the radio base station.

  In order to solve the above-described problems, the present invention has the following features. A first feature of the present invention is a radio base station that constitutes a radio communication system, and distance detection means (peripheral distance measurement unit 102, table generation unit 121) that detects a distance to an object with respect to a plurality of azimuth angles; Based on a plurality of the distances corresponding to the same azimuth angle stored in the storage means and storage means (storage unit 103) for storing the distance detected by the distance detection means, The gist of the present invention is to include a surrounding environment change detection (surrounding environment change detection unit 122) means for detecting a change in the surrounding environment.

  Such a radio base station detects a distance to an object with respect to a plurality of azimuth angles, and based on a plurality of distances corresponding to the same azimuth angle, for example, a new building is constructed, Detects changes in the environment around the radio base station due to the dismantling of. Therefore, when the environment around the radio base station changes, the change can be detected appropriately.

  A second feature of the present invention is that the surrounding environment change detecting means changes the surrounding environment of the radio base station when a plurality of the distances corresponding to the same azimuth angle stored in the storage means are different. The gist is to detect what has been done.

  A third feature of the present invention is that the surrounding environment change detection means is other than a distance to an object that exists only within a predetermined period among the plurality of distances corresponding to the same azimuth angle stored in the storage means. Based on this distance, the gist is to detect a change in the environment around the wireless base station.

  According to a fourth feature of the present invention, the surrounding environment change detecting means is a distance that occupies a majority of the plurality of distances corresponding to the same azimuth angle stored in the storage means and a first predetermined value or more. When a first distance having a difference is specified and a ratio of the number of the first distances to the number of the distances occupying the majority is equal to or smaller than a second predetermined value, a plurality of the corresponding distances corresponding to the same azimuth angle The gist is to exclude the first distance from the distance and detect a change in the environment around the radio base station based on the remaining distance.

  A fifth feature of the present invention includes a transmission unit (wired communication unit 104) that transmits information indicating a change in environment around the wireless base station detected by the surrounding environment change detection unit to another device. Is the gist.

  A sixth feature of the present invention is a surrounding environment change detection method in a radio base station constituting a radio communication system, wherein the radio base station detects a distance to an object with respect to a plurality of azimuth angles, A step in which the radio base station stores the detected distance, and a change in an environment around the radio base station based on a plurality of the distances corresponding to the same azimuth angle stored in the radio base station. And a step of detecting.

  ADVANTAGE OF THE INVENTION According to this invention, the change of the environment around a wireless base station can be detected appropriately.

1 is an external view of a radio base station according to an embodiment of the present invention. It is a figure which shows an example of the change of the surrounding environment of the wireless base station which concerns on embodiment of this invention. It is a block diagram of the radio base station which concerns on embodiment of this invention. It is a figure which shows a response | compatibility with the image data which concern on embodiment of this invention, and an azimuth-distance table. It is a flowchart which shows the operation | movement of the wireless base station which concerns on embodiment of this invention.

  Next, an embodiment of the present invention will be described with reference to the drawings. Specifically, (1) Configuration of the radio base station, (2) Operation of the radio base station, (3) Action and effect, (4) Other embodiments will be described. In the description of the drawings in the following embodiments, the same or similar parts are denoted by the same or similar reference numerals.

(1) Configuration of Radio Base Station FIG. 1 is an external view of the radio base station 100 according to the embodiment of the present invention. The radio base station 100 shown in FIG. 1 is based on, for example, 3GPP Release9 which is a 3.9 generation (3.9G) mobile phone system or LTE-Advanced which is positioned as a 4th generation (4G) mobile phone system. It has a configuration. The radio base station 100 includes an iron tower 160, a peripheral distance measuring unit 102 and an antenna 108 provided at the upper part of the iron tower 160, and a main body 150 provided at the lower part of the iron tower 160.

  FIG. 2 is a diagram illustrating an example of changes in the surrounding environment of the radio base station 100. When the periphery of the radio base station 100 changes from the state shown in FIG. 2A to the state where the building 200 is newly constructed as shown in FIG. 2B, the radio signal from the radio base station 100 is changed. The reach varies. In particular, in the direction from the radio base station 100 to the building 200, the radio signal from the radio base station 100 is difficult to reach farther than the building 200. On the other hand, even when an existing building is demolished around the radio base station 100, the reach of radio signals from the radio base station 100 changes. In the present embodiment, the radio base station 100 appropriately detects such a change in the surrounding environment.

  FIG. 3 is a configuration diagram of the radio base station 100 according to the embodiment of the present invention. The radio base station 100 includes a control unit 101, a peripheral distance measurement unit 102, a storage unit 103, a wired communication unit 104, a radio communication unit 106, and an antenna 108.

  The control unit 101 is configured using, for example, a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), and controls various functions provided in the radio base station 100. The storage unit 103 is configured using, for example, a memory, and stores various types of information used for controlling the radio base station 100 and the like.

  The peripheral distance measurement unit 102 is, for example, a camera that can be viewed stereoscopically and can capture the periphery of the radio base station 100 by 360 °. The peripheral distance measuring unit 102 captures the entire circumference of the azimuth angle of 0 ° to 360 ° in the horizontal direction around the radio base station 100 every time a predetermined predetermined shooting cycle (image data acquisition cycle) elapses. Is taken and image data is generated. The peripheral distance measurement unit 102 outputs the generated image data to the control unit 101.

  The wired communication unit 104 communicates with other devices such as an upper MME (Mobility Management Entity) and other radio base stations that perform various controls on the upper level of the radio base station 100 via a network (not shown). In communication between the radio base station 100 and the MME, for example, an S1 interface as a logical communication path is established in a network (not shown). In communication between the radio base station 100 and other radio base stations, for example, an X2 interface as a logical communication path is established in a network (not shown).

  The wireless communication unit 106 is configured using, for example, a radio frequency (RF) circuit, a baseband (BB) circuit, and the like, and transmits and receives a wireless signal to and from a wireless terminal (not shown) via the antenna 108. In addition, the wireless communication unit 106 performs encoding and modulation of the transmission signal and demodulation and decoding of the reception signal.

  The control unit 101 includes a table generation unit 121 and a surrounding environment change detection unit 122.

  Image data from the peripheral distance measurement unit 102 is input to the table generation unit 121. The table generation unit 121 is distance information indicating the distance to an object existing in the direction of the azimuth angle for each azimuth angle of 0 ° to 360 ° in the horizontal direction (for example, every 1 °) based on the image data. To get. The distance information is indicated by a value from 0 to 10, and the value decreases as the distance increases. If the distance to the object is greater than or equal to a predetermined distance, the distance information is zero.

  The table generating unit 121 equally divides the azimuth angle of 0 ° to 360 ° by a predetermined number to obtain a predetermined number of azimuth angle ranges. The table generation unit 121 calculates an average value of distance information corresponding to each azimuth included in the azimuth range for each predetermined number of azimuth ranges. The table generation unit 121 generates an azimuth-distance table composed of the average value of the calculated distance information for each azimuth range. Further, the table generation unit 121 stores the generated azimuth angle-distance table in the table database (DB) 131 configured in the storage unit 103 together with the generation date and time.

  FIG. 4 is a diagram showing the correspondence between the image data and the azimuth-distance table. FIG. 4 shows an example in which an azimuth angle of 0 ° to 360 ° is divided into 16 equal parts, and every 16 22.5 ° angle ranges obtained by 16 equal parts are included in the angle range. Sixteen average values of distance information corresponding to the azimuth are obtained, and an azimuth-distance table is generated. Comparing FIG. 4A and FIG. 4B, the azimuth-distance table shown in FIG. 4B indicates that the azimuth of FIG. It is different from the angle-distance table.

  The surrounding environment change detection unit 122 performs the following processing each time a predetermined surrounding environment change detection cycle elapses. First, the surrounding environment change detection unit 122 reads out a plurality of azimuth angle-distance tables whose corresponding generation dates / times are within the first past period from among the azimuth angle-distance tables currently stored in the table DB 131. .

  The surrounding environment change detection unit 122 is based on a plurality of read azimuth angle-distance tables, and among the plurality of distance information corresponding to the same azimuth angle range, an object that temporarily exists in the shooting range (within a predetermined period). Based on the distance information other than the distance information indicating the distance to the object (the only existing object), a change in the environment around the radio base station 100 is detected.

  Specifically, the surrounding environment change detection unit 122 extracts a plurality of pieces of distance information having different generation dates and times corresponding to the same azimuth range from the plurality of read out azimuth-distance tables. The surrounding environment change detection unit 122 is a distance other than distance information (first distance information) having a value that occupies a large number (for example, 9/10 or more of the whole) among a plurality of distance information corresponding to the same azimuth angle range. Information (second distance information) is specified. The second distance information is considered to indicate the distance to an object that temporarily exists in the shooting range, such as an automobile. Therefore, it is preferable that the second distance information is not used for detecting a change in the surrounding environment. For this reason, the surrounding environment change detection unit 122 excludes the second distance information from among a plurality of distance information corresponding to the same azimuth angle range.

  The surrounding environment change detection unit 122 calculates an average value of the remaining distance information (first distance information) corresponding to the same azimuth angle range. The surrounding environment change detection unit 122 generates an average azimuth-distance table composed of the azimuth angle range and the average value of the first distance information corresponding to the azimuth angle range. Furthermore, the surrounding environment change detection unit 122 stores the generated average azimuth angle-distance table in the table DB 131 in the storage unit 103 together with the generation date and time.

  Thereafter, the surrounding environment change detection unit 122 includes two average azimuth angle-distance tables that are continuous on the time axis from the table DB 131 in the storage unit 103, specifically, the latest average azimuth angle-distance table, one Read the previous average azimuth-distance table. The surrounding environment change detection unit 122 compares the two read average azimuth angle-distance tables and determines whether or not the two distance information corresponding to the same azimuth range is different.

  When two pieces of distance information corresponding to the same azimuth angle range are different, the surrounding environment change detection unit 122 detects that the surrounding environment has changed in the azimuth angle range. In this case, the surrounding environment change detection unit 122 detects the environment change including the azimuth angle corresponding to the azimuth angle range (for example, the azimuth angle at the center of the azimuth angle range) and the difference between the two distance information (distance change amount). Information is generated and output to the wired communication unit 104.

  The wired communication unit 104 transmits environment change detection information to an external device. The external device detects that there is a new object such as a building in the direction of the azimuth included in the environmental change detection information, or that the existing device does not exist due to the dismantling of the existing building. Thus, it can be recognized that the surrounding environment has changed.

(2) Operation of Radio Base Station Next, the operation of the radio base station 100 will be described. FIG. 5 is a flowchart showing the operation of the radio base station 100.

  In step S <b> 101, the radio base station 100 shoots using the entire circumference of the horizontal azimuth angle of 0 ° to 360 ° around the radio base station 100 as a shooting range, and generates image data.

  In step S102, the radio base station 100 acquires distance information indicating a distance to an object existing in the direction of the azimuth for each azimuth of 0 ° to 360 °.

  In step S103, the radio base station 100 generates and stores an azimuth-distance table including the azimuth angle range and the average value of the distance information corresponding to the azimuth angle range.

  In step S104, the radio base station 100 determines whether a time corresponding to the image data acquisition cycle has elapsed since the previous acquisition of the image data.

  When the time corresponding to the image data acquisition cycle has elapsed since the previous acquisition of the image data, in step S105, the radio base station 100 determines that the time corresponding to the peripheral environment change detection cycle has elapsed since the previous detection of the surrounding environment change. Determine whether or not.

  When the time corresponding to the surrounding environment change detection cycle has not elapsed since the previous surrounding environment change detection, the operations after the photographing of the surroundings of the radio base station 100 and the generation of the image data in step S101 are repeated.

  When the time corresponding to the surrounding environment change detection period has elapsed since the previous surrounding environment change detection, in step S106, the radio base station 100 determines that the azimuth-distance table generated within the past first period. Among the distance information corresponding to the same azimuth angle range, the distance information corresponding to the temporarily existing object is excluded.

  In step S107, the radio base station 100 calculates an average value of the remaining distance information corresponding to the same azimuth angle range, and based on the azimuth angle range and the average value of the remaining distance information corresponding to the azimuth angle range. An average azimuth-distance table is generated.

  In step S108, the radio base station 100 compares two average azimuth angle-distance tables that are continuous on the time axis, and determines whether or not the two distance information corresponding to the same azimuth range is different.

  If the two pieces of distance information corresponding to the same azimuth angle range are not different, the operations after photographing around the radio base station 100 and generating the image data in step S101 are repeated.

  If the two pieces of distance information corresponding to the same azimuth angle range are different, in step S109, the radio base station 100 determines the difference between the azimuth angle corresponding to the azimuth angle range and the two distance information (distance change amount). Is generated and transmitted to an external device. Thereafter, the operations after the photographing of the periphery of the radio base station 100 and the generation of the image data in step S101 are repeated.

(3) Operation / Effect The radio base station 100 according to the embodiment of the present invention performs imaging using the entire circumference of the azimuth angle of 0 ° to 360 ° around the radio base station 100 as a shooting range, and based on the image data. The distance information indicating the distance to the object is acquired. Furthermore, when the two distance information acquired at different timings corresponding to the same azimuth angle range is different, the radio base station 100 detects that the environment around the radio base station 100 has changed. Therefore, when the environment around the radio base station 100 changes, the change can be detected appropriately.

  Also, the radio base station 100 uses the distance information indicating the distance to an object that temporarily exists in the shooting range (an object that exists only within a predetermined period) among a plurality of distance information corresponding to the same azimuth angle range. Is not used for detecting changes in the environment around the radio base station 100. Therefore, it is possible to appropriately detect a change in the environment over a long period of time, which requires the communication area of the radio base station 100 to be optimized.

(4) Other Embodiments As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the embodiment described above, the radio base station 100 determines whether or not the two distance information corresponding to the same azimuth range is different, but the difference between the two distance information corresponding to the same azimuth range is a predetermined value. It is determined whether or not the value is equal to or smaller than the value, and when the value is equal to or smaller than the predetermined value, the environment change detection information including the azimuth corresponding to the azimuth range and the difference between the two distance information (distance variation) is generated , You may send.

  In the above-described embodiment, the peripheral distance measurement unit 102 is a camera that can be viewed stereoscopically and can photograph the periphery of the radio base station 100 by 360 °. However, the peripheral distance measurement unit 102 may be a radar that receives reflected waves by irradiating the entire circumference of 360 ° around the radio base station 100 with electromagnetic waves. In this case, the table generation unit 121 determines, for each azimuth angle from 0 ° to 360 °, an object that exists in the direction of the azimuth angle, based on the time from when the radar radiates electromagnetic waves until the reflected wave is received. The distance information indicating the distance can be acquired.

  In the embodiment described above, the radio base station 100 transmits the environmental change detection information to an external device, and the external device uses the received environmental change detection information to determine the direction of the azimuth included in the environmental change detection information. , We recognized that the surrounding environment had changed due to the existence of new objects such as buildings and the absence of existing objects. However, the radio base station 100 itself uses the environmental change detection information to indicate that there is a new object or no existing object in the direction of the azimuth angle included in the environmental change detection information. You may make it recognize that the environment changed.

  In the embodiment described above, the wireless communication system 1 is configured based on 3GPP Release 9 or LTE-Advanced, but may be configured based on other communication standards.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

  DESCRIPTION OF SYMBOLS 100 ... Wireless base station, 101 ... Control part, 102 ... Ambient distance measurement part, 103 ... Memory | storage part, 104 ... Wired communication part, 106 ... Wireless communication part, 108 ... Antenna, 121 ... Table production | generation part, 122 ... Surrounding environment change Detection unit, 131 ... table DB, 150 ... main body

Claims (6)

A radio base station constituting a radio communication system,
Distance detecting means for detecting the distance to the object for a plurality of azimuth angles;
Storage means for storing the distance detected by the distance detection means;
A radio base station comprising: a surrounding environment change detecting unit that detects a change in environment around the radio base station based on a plurality of the distances corresponding to the same azimuth angle stored in the storage unit.   The surrounding environment change detection unit detects that the surrounding environment of the radio base station has changed when a plurality of the distances corresponding to the same azimuth angle stored in the storage unit are different. The radio base station described.   The surrounding environment change detection unit is configured to detect the radio base station based on a distance other than a distance to an object that exists only within a predetermined period among a plurality of the distances corresponding to the same azimuth angle stored in the storage unit. The radio base station according to claim 1, wherein a change in an environment around the station is detected.   The surrounding environment change detecting means identifies a first distance having a difference equal to or greater than a first predetermined value from a plurality of the distances corresponding to the same azimuth angle stored in the storage means. When the ratio of the number of the first distances to the number of the distances occupying the majority is equal to or less than a second predetermined value, the first distance is excluded from a plurality of the distances corresponding to the same azimuth angle. The radio base station according to claim 1, wherein a change in environment around the radio base station is detected based on the remaining distance.   5. The radio base station according to claim 1, further comprising: a transmission unit that transmits information indicating a change in an environment around the radio base station detected by the surrounding environment change detection unit to another apparatus. A surrounding environment change detection method in a radio base station constituting a radio communication system,
The wireless base station detecting a distance to an object for a plurality of azimuth angles;
The wireless base station storing the detected distance;
The wireless base station detecting a change in the environment around the wireless base station based on the plurality of distances corresponding to the same stored azimuth angle.

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