JP2009111760A - Radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a radio communication system capable of transmitting a signal prompting the installation of a relay apparatus, from a base station to a moving radio terminal in a situation where no relay apparatus is fixed beforehand. <P>SOLUTION: The radio communication system includes a plurality of mobile terminals, a base station with these terminals under control and a relay apparatus, wherein prior to starting communication, the base station calculates a radio reach range depending on a reference value based on performance resources, expansion routes and map data of the mobile terminals and calculates a radio reach range depending on a theoretical value by applying, to the calculated radio reach range, geographical information of obstacles or the like on an activity site and additional conditions such as weather, route fault and the like. Further, after starting communication with a radio terminal, based on location information of the radio terminal and a measured parameter of a radio signal, the base station calculates a radio reach range, depending on a measured value, in which stable communication with the radio terminal can be maintained and ensured. If the location of the radio terminal comes near getting out of the range, a signal prompting the installation of the relay apparatus is sent to the radio terminal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio communication system, and more particularly to a radio communication system for maintaining communication between a base station and a moving radio terminal while installing the relay apparatus at an appropriate position even in a situation where the relay apparatus cannot be fixed in advance. About.

Conventionally, when a mobile radio terminal and a base station communicate with each other, a radio communication system is known that passes through a relay device installed in the middle of the communication path in order to maintain communication between them (for example, , See Patent Document 1). In order to ensure the necessary radio coverage, the relay device is pre-determined based on the performance specifications of the radio terminal and base station, topography within the target range, obstacles, etc., and is fixed at that location. The And the radio | wireless communications system which consists of a radio | wireless terminal and base station containing these relay apparatuses is maintained as a communication infrastructure prepared by the carrier, or a communication infrastructure for specific object business, for example. (For example, refer to Patent Document 2). In the case disclosed in Patent Document 2, a radio apparatus with a short transmission distance is used by installing a relay device that relays the GPS reception information of the fixed station to the mobile body within the reach of the radio wave from the fixed station. Meanwhile, the mobile body calculates its own three-dimensional coordinates in real time from the GPS reception information of the relayed fixed station and its own GPS reception information.
JP-A-9-238119 (4th page, FIG. 1) JP-A-9-281210 (5th page, FIG. 1)

  By the way, in various activities in the harsh outdoor environment, such as disaster rescue operations, the base station, which serves as a command center for grasping and consolidating the status of activities, carries each worker in order to proceed safely and smoothly. It is indispensable to always stably secure communication means between wireless terminals or between wireless terminals. On the other hand, in the target areas of these activities, the wireless communication infrastructure is not always well prepared and available. Rather, assuming that it is difficult to use, for example, while building and developing a unique communication network that includes a base station and a moving wireless terminal, as well as a relay device installed to secure a desired wireless reachable range Activities are promoted.

  However, in such an activity site, each worker is moving while moving, and the radio coverage is constantly changing. In addition, as the activity progresses, the activity area also changes from time to time, and the wireless reachable range to be secured changes accordingly. In addition, the conditions specific to the activity site that affect wireless communication also vary in various ways. For this reason, when deploying a wireless communication network, there has been a problem that it may be difficult to determine and fix the position where the relay device is installed in advance in order to secure a desired wireless reachable range.

  The present invention has been made in consideration of the above-described circumstances, and in a situation where the relay device is not fixed in advance, wireless communication that transmits a signal prompting the wireless terminal moving from the base station to install the relay device The purpose is to provide a system.

  To achieve the above object, a wireless communication system of the present invention includes a plurality of wireless terminals that move while reporting self-location information, a base station that has these wireless terminals, the wireless terminal, and the base station. In the wireless communication system having a relay device that relays communication between the base station, the base station transmits / receives a wireless signal to / from the wireless terminal, a self-position acquiring unit that acquires self-position information, and the wireless terminal Terminal basic information table including performance specifications and deployment route, map file for storing map information, calculation unit for calculating radio coverage, and input of topographic information and incidental conditions used for calculation of radio coverage An operation display unit that receives and displays a calculation result in the calculation unit, and before starting communication with the wireless terminal, in the calculation unit, the terminal basic information table, And a first wireless reachable range based on the map file and a second wireless reachable range to which the terrain information and incidental conditions are further added are calculated and displayed on the operation display unit to communicate with the wireless terminal. After the start, the calculation unit calculates a third wireless reachable range based on the position information of the wireless terminal, the level of the wireless signal, and the data error occurrence frequency, and displays it on the operation display unit. Is transmitted to the wireless terminal when it enters the predetermined edge of the third wireless reachable range, and a signal prompting the wireless terminal to install the relay device is transmitted.

  According to the present invention, since the base station transmits a signal prompting the installation of the relay device to the mobile radio terminal, it is possible to install the relay device at an appropriate position, so that the relay device cannot be fixed in advance. A wireless communication system capable of maintaining wireless communication even in an environment can be obtained.

  The best mode for carrying out a wireless communication system according to the present invention will be described below with reference to FIGS.

  FIG. 1 is a block diagram showing a configuration of an embodiment of a radio communication system according to the present invention. In this example, the case where there are one wireless terminal and one relay device is illustrated. As illustrated in FIG. 1, the wireless communication system includes a wireless terminal 10, a relay device 20, and a base station 30. The radio terminal 10 communicates a message including the self-location information, the radio signal level, and the data error occurrence frequency report directly or via the relay device 20 with the radio signal. The relay device 20 relays communication between the wireless terminal 10 and the base station. The base station 30 calculates a wireless reachable range while performing message communication with the wireless terminal 10 directly or via the relay device 20 by a wireless signal, and based on the calculation result, the base station 30 Send a signal to encourage installation.

  In the present embodiment, the wireless terminal 10 includes a self-position acquisition unit 11 that acquires self-position information by GPS, and a transmission / reception unit 12 that transmits and receives a wireless signal while acquiring a wireless signal level and data error occurrence frequency. ing. The relay device 20 includes a self-location information acquisition unit 21 that acquires self-location information by GPS, and a relay unit 22 that relays communication using radio signals between the radio terminal 10 and the base station 30. The base station 30 includes a self-position acquisition unit 31, a transmission / reception unit 32, a calculation unit 33, an operation display unit 34, a terminal basic information table 35, and a map file 36.

  The self-position acquisition unit 31 acquires self-position information by GPS and sends it to the calculation unit 33. The transmission / reception unit 32 transmits / receives a wireless signal to / from the wireless terminal 10 or the relay device 20 while acquiring the wireless signal level and data error occurrence frequency. The computing unit 33 calculates the wireless reachable range based on the self-location information, the level of the radio signal, the terrain information from the terminal basic information table 35, the map file 36, and the operation display unit 34 described later, and incidental conditions. Based on the result, a signal that prompts the wireless terminal 10 to install the relay device 20 is generated. The operation display unit 34 receives various operation inputs including terrain information and incidental conditions input by an operator or the like, and displays the wireless reachable range calculated by the calculation unit 33. In the present embodiment, the input terrain information includes obstacle information that affects wireless communication at the activity site, for example, positions and areas of buildings and forests that are not explicitly shown in the map file 36 described later. The incidental conditions also include, for example, attenuation information due to weather and communication path failure information that influences wireless communication depending on the occasion at the activity site.

  The terminal basic information table 35 is set in advance as a table including performance specifications and deployment routes of each of the plurality of wireless terminals 10. An example of the terminal basic information table in the present embodiment is shown in FIG. In the case of FIG. 2, in addition to a unique terminal number and owner, transmission power and frequency as performance specifications, and a planned movement point after a predetermined time have been sequentially deployed as a deployment route for each wireless terminal 10. It shows the case of setting. The map file 36 is a numerical map database that includes elevation and digitizes a topographic map.

  In the configuration of the base station 30, the calculation unit 33, the operation display unit 34, the terminal basic information table 35, and the map file 36 are implemented on a general-purpose computer system such as a personal computer or a workstation. can do. An example of the configuration of these computer systems is shown in FIG. This computer system includes a CPU 41, a memory 62, an input device 63, an output device 64, an input / output interface 65, an HDD 66, and an external storage device 67.

  The CPU 61 controls the entire computer system, and executes various processes according to programs for realizing various calculation functions developed in the memory 62 including calculation calculation of the wireless reachable range. The input device 63 includes, for example, a keyboard, a mouse, and the like, and receives various operation inputs including topographic information and incidental conditions input by the above-described operator or the like. The output device 64 is composed of, for example, a CRT display or an LCD display, and performs display accompanying an input operation by an operator or various information processing results in addition to the calculation result of the wireless reach. The input / output interface 65 exchanges data with each unit including the self-position acquisition unit 31 and the transmission / reception unit 32. The HDD 66 stores a program for realizing various information services including the calculation function of the calculation unit 33, and the stored program is transferred to the memory 62 when the function is executed. The external storage device 67 is a large-capacity storage device, and stores and stores various data including the terminal basic information table 35 and the map file 36.

  Next, the operation of the wireless communication system of the present embodiment configured as described above will be described with reference to FIGS. 1 to 3 and the flowchart of FIG. 4 and the explanatory diagram of FIG. In the following description, the description will be given centering on the base station with one wireless terminal 10. FIG. 4 is a flowchart for explaining the operation of the embodiment of the wireless communication system according to the present invention illustrated in FIG.

  First, when the base station 30 starts operation, the computing unit 33 refers to the terminal basic information table 35 and acquires the performance specifications and the deployment route of each wireless terminal 10 (ST401). Next, the calculation unit 33 receives the self-location information acquired by the self-location information acquisition unit 31. This self-location information is acquired using GPS, and is expressed by, for example, latitude and longitude (ST402). Further, based on the self-location information, map data around the self-location is read from the map file 36 (ST403). And the radio | wireless reachable range by the reference value which is a 1st wireless reachable range is calculated, and it displays on the operation display part 34 (ST404).

  Subsequently, the calculation unit 33 receives the terrain information and incidental conditions received by the operation display unit 34. In this embodiment, the terrain information is the position and area information of obstacles that affect wireless communication at the activity site, and the incidental conditions include weather information and communication path failure information as elements that affect wireless communication in the short term. (ST405). Then, these are applied to the wireless reachable range based on the reference value calculated in step ST404, and the wireless reachable range based on the theoretical value, which is the second wireless reachable range, is calculated and superimposed on the operation display unit 34. An example of the display screen of the operation display unit 34 up to this step is illustrated in FIG. In the case of FIG. 5A, the wireless reachable range 512 based on the reference value calculated in the step ST404, the wireless reachable range 513 based on the theoretical value calculated in this step, and the ST405 around the position 511 of the base station 30. An obstacle region 514 based on the topographic information received in step (ST406) is displayed.

  After these processing steps are performed, the wireless terminal 10 starts communication with the base station and is carried by, for example, a worker or the like. During movement, the wireless terminal 10 uses the GPS to acquire its own position information by using, for example, latitude / longitude in the own position acquisition unit 11. When the transceiver unit 12 receives a radio signal from the base station 30, the level and data error occurrence frequency are acquired. Then, the base station 30 is notified of the acquired self-location information, radio signal level, and data error frequency. Various settings can be selected in accordance with the operation status, for example, every predetermined time interval corresponding to the moving speed or every predetermined moving distance.

  When the base station 30 receives a report from the radio terminal 10 (ST407), the base station 30 determines the position of the radio terminal 10, the level of each other's radio signal, and the frequency of data error according to the theoretical values calculated in step ST406. Applying to the wireless reachable range, the wireless reachable range based on the actually measured value that is the third wireless reachable range is calculated. That is, here, the wireless reachable range in which communication can be stably maintained is recalculated based on actually measured parameter values in actual wireless communication. Then, the calculation result is displayed on the operation display unit 34. An example of the display screen of the operation display unit 34 at this step is illustrated in FIG. In the case of FIG. 5B, in addition to the display in step ST406, the position 515 based on the position information of the wireless terminal 10 obtained in the previous step, and the wireless reachable range 516 based on the actually measured value calculated in this step. Is drawn (ST408).

  Further, the computing unit 33 in the base station 30 determines whether or not the wireless terminal 10 is within the wireless reachable range 516 calculated in step ST408 based on the position information from the wireless terminal 10 displayed at the position 515. To do. When the wireless terminal 10 enters a predetermined distance range from the boundary of the wireless reachable range 516, that is, when it is likely to deviate from the wireless reachable range 516 (Y in ST409), the base station 30 The signal which urges installation of 20 is transmitted. This signal is received on the wireless terminal 10 side, and is notified to, for example, a worker carrying the wireless terminal 10 by a display lamp, a display message, a voice message, or the like (ST410).

  After this, when the relay device 20 is installed and the relay device 20 also acquires its own position by GPS and starts reporting to the base station 30, the measured values including the relay device 20 are repeated while repeating the steps from ST407 described above. The wireless reachable range is recalculated and drawn on the operation display unit 34. An example of a display screen after installing the relay device 20 is illustrated in FIG. In the case of FIG. 5C, the position 517 of the newly installed relay device 20 and the wireless reachable range 516a based on the recalculated actual measurement values are drawn with respect to the case of FIG. 5B. . Then, the above-described operation is repeated until the operation end is instructed (ST411).

  As described above, in this embodiment, in a wireless communication system having a plurality of mobile terminals, a base station having them, and a relay device, the base station performs various performance characteristics of the mobile terminal before starting communication. Based on the original and development routes, and map data, the wireless reach by reference values, and by applying terrain information such as obstacles at the activity site and incidental conditions such as weather and route obstacles, wireless reach by theoretical values Each range is calculated and displayed. Furthermore, after starting communication with the wireless terminal, the base station calculates a wireless reachable range based on measured values that can maintain and ensure stable communication with the wireless terminal based on the position information of the wireless terminal and the measured parameters of the wireless signal. Yes. When the position of the wireless terminal is likely to be out of this range, a signal that prompts the wireless terminal to install a relay device is transmitted.

  As a result, a relay device can be installed at an appropriate position, and wireless communication that can maintain wireless communication even in a communication environment where the relay device cannot be fixed in advance, such as in an area where communication infrastructure is insufficiently established. A communication system can be obtained. In addition, since the calculation results and the positions associated with the deployment of the relay device and the mobile terminal are displayed on the operation display unit of the base station, the base station side efficiently operates the radio communication system while checking the radio reachable range. It becomes possible to do.

  Note that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The block diagram which shows the structure of one Example of the radio | wireless communications system which concerns on this invention. Explanatory drawing which shows an example of a terminal basic information table. The block diagram which shows an example of a structure of the computer system used for a base station. 3 is a flowchart for explaining the operation of the wireless communication system illustrated in FIG. 1. Explanatory drawing which shows an example of a display screen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wireless terminal 11, 21, 31 Self-position acquisition part 12, 32 Transmission / reception part 20 Relay apparatus 22 Relay part 30 Base station 33 Calculation part 34 Operation display part 35 Terminal basic information table 36 Map file

Claims (4)

Multiple wireless terminals that move while reporting self-location information,
A base station with these wireless terminals under control,
In a wireless communication system having a relay device that relays communication between the wireless terminal and the base station,
The base station
A transmission / reception unit that exchanges radio signals with the wireless terminal;
A self-position acquisition unit that acquires self-position information;
A terminal basic information table including performance specifications and deployment routes of the wireless terminal;
A map file that stores map information;
A calculation unit for calculating a wireless coverage area;
An operation display unit that accepts input of topographic information and incidental conditions used for calculation of the wireless reach, and displays a calculation result in the calculation unit,
Before starting communication with the wireless terminal, a second wireless range based on the terminal basic information table and the map file, and further adding the topographic information and incidental conditions in the computing unit. Each wireless reachable range is calculated and displayed on the operation display unit,
After starting communication with the wireless terminal, the calculation unit calculates a third wireless reachable range based on the position information of the wireless terminal, the level of the wireless signal, and the frequency of data error occurrence, and displays the operation display unit. Display
A wireless communication system, wherein when the wireless terminal enters a predetermined edge of the third wireless reachable range, a signal that prompts the wireless terminal to install the relay device is transmitted.   The wireless communication system according to claim 1, wherein the wireless terminal acquires self-location information by GPS.   The wireless communication system according to claim 1 or 2, wherein the self-position acquisition unit of the base station acquires self-position information by GPS.   The relay device includes a self-position acquisition unit that acquires self-position information by GPS, and reports the acquired self-position information to the base station and the mobile terminal. A wireless communication system according to claim 1.

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