JP2005056102A - Environment monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an integral environment monitoring system for setting a monitor camera, and for flexibly coping with the collection of environment information even in a place where the maintenance of a communication network is insufficient. <P>SOLUTION: This radio transmitter/receiver for communicating with a radio base station is mounted on an information collecting terminal or a network camera. An environment information DB for managing environment information from the information collecting terminal, a terminal information DB for managing the information of the information collecting terminal, and a base station information DB for managing information associated with the radio base station are connected to the management server. A function for acquiring and displaying a video transmitted from the network camera and the environment information transmitted from the information collecting terminal is mounted on the management server. A first communication interface which can be connected to a public network or LAN, a second communication interface for executing radio communication with the information collecting terminal, and a third communication interface for relay are mounted on the radio base station. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an environmental monitoring system that is used, for example, for environmental surveys in the field, biological ecological surveys, and monitoring of illegal dumping.

Conventionally, when monitoring an environmental crime such as illegal dumping, a remote monitoring system using a monitoring camera has been used.
Patent Documents 1 and 2 are known as conventional techniques related to such a remote monitoring system. Patent Document 1 discloses a method of photographing a vehicle or illegal dumping and automatically detecting it by image processing, and Patent Document 2 discloses a method in which a supervisor performs camera control from a remote place.

  For example, as shown in Patent Document 3 and Patent Document 4, an environment monitoring system that measures noise, vibration, water quality, water level, temperature, humidity, and the like and browses it at a remote place is also known. Such an environmental monitoring system transfers information obtained from a sound level meter, a vibration meter, a PH sensor, a temperature sensor, a humidity sensor, etc. to a device existing at a remote location, and records, processes and displays the environmental information at a remote location. Making it possible.

On the other hand, the environmental information collection system disclosed in Patent Document 5 enables the collection of image, voice, and character information linked with local location information, and efficiently collects the collected information, thereby efficiently. Accumulate and manage environmental information. Further, the technique disclosed in Patent Document 6 proposes to efficiently process environmental information related to product parts and materials.
JP 2002-334386 A Japanese Patent Laid-Open No. 2003-8761 JP 2001-325682 A Japanese Patent Laid-Open No. 10-82668 JP 2002-123557 A JP 2002-92093 A JP 2003-85677 A JP 2002-77882 A JP 2001-285507 A

As described above, due to increasing interest in the environment in recent years, it is desired to develop an environmental monitoring system that can effectively collect and process environmental information and can flexibly monitor the environment such as illegal dumping.
In recent years, due to the high cost of processing industrial waste, illegal dumping of industrial waste illegally performed in mountainous areas, which are less popular, has become an agenda. Illegal dumping is often performed in a time zone where it is difficult to find in a place where it is difficult for a third party to find it, and it is difficult to crack down only with patrol. Therefore, it is common to install a TV camera in a place where there is a high possibility of illegal dumping and always take pictures of a specific place and discover the act itself.

In addition, there are many places where illegal dumping is not possible in less popular places, so in order to sufficiently monitor illegal dumping, a large number of TV cameras are installed at points distant from each other. Therefore, it is necessary to connect them to a predetermined communication network. However, there are many cases where the communication network necessary for remote monitoring is not sufficiently provided in such a place.
For this reason, when a system for monitoring illegal dumping is installed, it is necessary to construct a new communication network, and it is expected that enormous costs will be incurred.

  For example, in the remote monitoring system disclosed in Patent Document 7 and Patent Document 8 and the water quality monitoring system disclosed in Patent Document 9, it is mainly connected to a communication network such as the Internet, a public network, and a mobile phone network. Assumed. However, for example, even in the case of a mobile phone network with a high coverage ratio, there are many cases where it is often outside the service area in a less popular mountainous area. Therefore, the conventional system has a problem in feasibility.

Also, in the environmental information collection system used when the investigator visits the site and collects environmental information, collect as much information as possible once and mainly use an existing communication network such as a mobile phone network. It is assumed that all data will be transferred at once. Therefore, there is a high possibility that inconvenience occurs in collecting important environmental information in a less popular place.
It is an object of the present invention to provide an integrated environmental monitoring system that can install a monitoring power mela in a place where communication network is insufficiently maintained and can flexibly cope with the collection of environmental information. To do.

  The first invention (Claim 1) is an information collection terminal for collecting at least one kind of environmental information obtained by measurement of temperature, humidity, air quality, water quality, soil quality, noise, vibration, etc. or biobiological survey, A network camera that captures images used for remote monitoring of illegal dumping, remote observation of the natural environment, and the information collection terminal and network camera via a predetermined network, and management of the network camera and the information collection In an environment monitoring system including a management server that manages environmental information collected by a terminal and at least one wireless base station that can be connected to communication facilities such as a public network and a LAN, the information collection terminal includes: To detect at least one of temperature, humidity, air quality, water quality, soil quality, noise and vibration as part of environmental information According to the input to the environment information sensor, the operation information input device that accepts input of the user's voice or character information for operation, the position information acquisition device, and the input to the operation information input device, the information of the image or video is An information recording device that collects as part and records the positional information obtained by the positional information acquisition device in association with the acquired environmental information, and an information display device that displays the environmental information and positional information in association with each other And a wireless transmission / reception device for communication with the wireless base station, and the network camera has a wireless transmission / reception device for communication with the wireless base station. Are an environment information database that manages environment information transmitted from the information collection terminal, and an terminal that manages information about the information collection terminal. Equipped with a function to connect an information database to a base station information database that manages information related to the radio base station, and to acquire and display video sent from the network camera and environmental information sent from the information collection terminal The wireless base station includes at least one first communication interface for connecting to a public network or a LAN, and at least one second communication interface for performing wireless communication with the information collection terminal. And at least one third communication interface for wireless communication between wireless base stations for relaying.

  In the first invention, since the radio base station is equipped with the first communication interface, the second communication interface, and the third communication interface, it is connected to the public network or the LAN using the first communication interface. An access wireless channel for wireless communication with the information collecting terminal can be secured using the second communication interface, and between the wireless base stations for relaying using the third communication interface. A wireless channel for relay for wireless communication can be secured.

  Therefore, even in a place where a communication network is not established, a plurality of wireless base stations are arranged at an arbitrary place and one wireless base station is connected to a public network or a LAN so that a monitoring network camera or A new communication network for the information collection terminal to communicate can be constructed using only a wireless medium. For this reason, it is possible to flexibly install a monitoring network power camera even in an unpopular place.

  The information collection terminal can access a management server that centrally manages environmental information and communicate with other terminals by using a wireless communication network that can be easily constructed even in places where communication networks are not yet developed. Become. Further, since the second communication interface and the third communication interface are provided in each radio base station to separate the access radio channel and the relay radio channel, it is possible to reduce the delay of video transmission.

  According to a second invention (Claim 2), in the first invention, when the management server gives the information collection terminal permission to use a communication network including the base station, the second information is unique to the information collection terminal. The network interface address assigned to the terminal is registered in the terminal information database, and the information registered in the terminal information database is distributed to all available wireless base stations. A connection request from the information collection terminal is identified based on the contents of the terminal information database distributed from a server, and an address of a network interface uniquely assigned to the information collection terminal is registered in the terminal information database. Only accept the connection, and before each connection, a different network address is Assigned to the information collection terminal, information representing a correspondence relationship between addresses of the network address and network interface, configured to deliver to the management server and the other wireless base station.

In the second aspect of the invention, it is possible to prevent an information collecting terminal registered in the terminal information database or a terminal other than the network camera from illegally using a communication network constituted by the wireless base station.
According to a third invention (Claim 3), in the second invention, when the wireless base station approves the connection of the information collecting terminal, the wireless base station is encrypted with a unique encryption key for each session. A pair of a decryption key for decrypting information is created, the encryption key is notified to the information collection terminal, and the encryption key and the network address are associated with each other and stored in the terminal information database. The information collection terminal that receives the encrypted information is notified of the decryption key each time, and in communication in the wireless section, for each session (a state in which a connection with an approved connection is maintained) A communication frame encrypted using an encryption key is used for communication. In the third aspect of the invention, each radio base station becomes an authentication station, and an encryption key is issued for each connection between the radio base station and the information collecting terminal, and communication frames in the radio section are encrypted using this encryption. , Can transmit information safely.

  According to a fourth invention (Claim 4), in the second invention, when the information collection terminal makes a connection request to the radio base station, each radio base station uses the second communication interface. The access control signal to be transmitted periodically is received, the reception strength of the received access control signal is greater than or equal to a predetermined value, and the radio base station with the smallest number of other information collection terminals already connected is selected, A connection request is made to the selected radio base station. In the fourth aspect of the invention, when selecting a radio base station to which a new information collecting terminal that joins the network is connected, the optimum selection is performed using the received signal strength and the number of connected terminals as parameters. It is possible to avoid the concentration of traffic on the radio base station.

  According to a fifth invention (Claim 5), in the first invention, the wireless base station connects to another wireless base station that has already formed a communication network and participates in the communication network. , Each radio base station receives the inter-base station communication control signal periodically transmitted using the third communication interface, and the received intensity of the received inter-base station communication control signal is a predetermined value or more, A wireless base station with the smallest number of other wireless base stations already connected is selected, and a connection request is made to the selected wireless base station. In the fifth aspect of the present invention, when newly connecting a wireless base station to extend the service area of the wireless communication network, the reception strength of the communication signal between the wireless base stations and the number of connected wireless base stations are parameters. As a result, it is possible to avoid the concentration of traffic between specific base stations.

  According to a sixth invention (Claim 6), in the first invention, when the wireless base station receives communication frames from a plurality of the network cameras and information collecting terminals at the same time, it transmits video and audio communication frames. It is configured to process with priority over a communication frame composed of other information and transmit it to other radio base stations and management servers. In the sixth aspect of the invention, scheduling is performed so that communication frames with high real-time properties such as video and audio are transmitted preferentially. Therefore, in an environment monitoring system in which various media are mixed, video and audio communication quality is improved. be able to.

  According to a seventh invention (Claim 7), in the first invention, an information disclosure server for providing environmental information collected by the management server to a specific user, and information relating to a user who is an information disclosure target are managed. And a user information database. Thereby, the environment information collected by the management server can be provided to a specific user having authority.

  According to the present invention, even in a place where a communication network is not established, a plurality of wireless base stations are arranged at an arbitrary place, and one wireless base station is connected to a public network or a LAN for monitoring. A new communication network for communication between the network camera and the information collecting terminal can be constructed using only a wireless medium. For this reason, it is possible to flexibly install a monitoring network power camera even in an unpopular place. In addition, video and environment information collected by a network camera and an information collection terminal can be managed in a centralized manner by a management server.

  Further, by restricting information collecting terminals that can participate in the network and dynamically assigning network addresses to the participating information collecting terminals, unauthorized access to information terminals can be eliminated. Further, regarding the connection between the radio base station and the information collection terminal, unauthorized access and information tampering can be prevented by using a communication frame encrypted by assigning a unique encryption key for each session.

  In addition, when the information collection terminal makes a connection request to the radio base station, the reception strength of the access control signal periodically transmitted by all the radio base stations out of all connectable radio base stations exceeds a certain value. In addition, by making a connection request to the radio base station having the smallest number of other information collection terminals already connected, it is possible to avoid the concentration of traffic on a specific radio base station. Also, when a new wireless base station joins the network, the reception strength of the inter-base station communication control signal periodically transmitted by all the base stations out of all connectable wireless base stations exceeds a certain value. In addition, by making a connection request to a radio base station having the smallest number of other radio base stations that are already connected, it is possible to avoid the concentration of traffic between specific radio base stations. Further, by performing scheduling that gives high priority to communication packets with high real-time properties such as video and audio, the communication quality of video and audio can be improved.

(First embodiment)
One embodiment of the environmental monitoring system of the present invention will be described with reference to FIGS. This form corresponds to claim 1.
FIG. 1 is a block diagram illustrating a configuration example of a system. FIG. 2 is a block diagram illustrating a configuration example of a radio base station. FIG. 3 is a block diagram showing an example of radio channel assignment. FIG. 4 is a flowchart showing radio channel assignment processing. FIG. 5 is a block diagram illustrating a configuration example of the information collection terminal.

  In this embodiment, the information collection terminal, network camera, management server, wireless base station, environmental information sensor, operation information input device, position information acquisition device, information recording device, information display device, wireless transmission / reception device, environmental information of claim 1 The database, terminal information database, base station information database, first communication interface, second communication interface, and third communication interface are an information collection terminal 108, a network camera 109, a management server 104, a wireless base station 107, and an environment, respectively. Information sensor 505, voice input device 502 (503), position information acquisition device 508, information storage device 507, information display device 506, wireless transmission / reception device 509, environment information DB (database, the same applies hereinafter) 102, terminal information DB 101, base station Information DB 103, routing control device 2 5, corresponding to the access transceiver 204 and the relay transceiver 203.

As shown in FIG. 1, the environmental monitoring system of this embodiment includes a terminal information DB 101, an environmental information DB 102, a base station information DB 103, a management server 104, an environmental information display device 105, a public network 106, a wireless base station 107, and an information collecting terminal. 108 and a network camera 109.
The terminal information DB 101 is provided for accumulating and managing information related to the information collection terminal 108. The environment information DB 102 is provided for accumulating and managing the collected environment information. The base station information DB 103 is provided for managing information related to the connected radio base station, for example, information on the network address of the radio base station, the address of the network interface, information on the connection status, and the like.

The management server 104 is provided for managing the information collection terminal 108, the radio base station 107, environment information, and the like. The environment information display device 105 is provided for displaying the collected environment information, monitoring video, and the like.
The terminal information DB 101, the environment information DB 102, the base station information DB 103, the management server 104, and the environment information display device 105 can be installed in an area where communication facilities are prepared, for example, in a management center in an urban area. The management server 104 is connected to a predetermined public network 106. Of course, instead of the public network 106, it may be connected to a communication network such as a LAN (Local Area Network).

In this form, it is assumed that environmental information and the like are collected in a monitoring target area (an area surrounded by a virtual line in the figure: a dead zone) where communication facilities are not yet developed like a mountainous area. In order to enable communication using a wireless medium at an arbitrary point in this region, a plurality of wireless base stations 107 (1), 107 (2), 107 (3), 107 (4), 107 (5), 107 (6) and 107 (7) are arranged.
One radio base station 107 (1) is installed at a position where it can be connected to the public network 106, and the connection terminal 211 of the radio base station 107 (1) is connected to the public network 106 by wire.

In the example shown in FIG. 1, information collection terminals 108 (1), 108 (2), 108 (3),... And network cameras 109 (1), 109 (2),. is set up.
Each radio base station 107 includes an access communication channel for communication between each information collection terminal 108 and the network camera 109 and a relay communication channel for communication between the radio base stations.

Each wireless base station 107 is portable and is configured so that the installation position can be changed as necessary. Accordingly, after each information collection terminal 108 or network camera 109 is installed at a position where information should be collected, each radio base station 107 may be installed at a position where it can communicate with each information collection terminal 108 and network camera 109.
In addition, the radio base station 107 cannot be directly communicated with the radio base station 107 (1) connected to the public network 106, or cannot be communicated with other radio base stations 107 that can communicate with the radio base station 107 (1). If it exists, the configuration of the route may be changed so that another radio base station 107 is arranged in the vicinity thereof to relay communication.

  As described above, even in a dead zone where the existing communication facilities are not sufficiently developed and cannot be covered as a communication area, the portable radio base station 107 is arranged to collect environmental information using the information collection terminal 108 or to create a network. An environmental monitoring system used for illegal dumping monitoring using the camera 109 can be realized. In other words, the survey area can be expanded more flexibly because it does not depend much on the existing communication facilities.

  Each radio base station 107 used in this form is configured as shown in FIG. 2, for example. Referring to FIG. 2, the radio base station 107 includes a relay antenna 201, an access antenna 202, a relay transceiver 203, an access transceiver 204, a routing controller 205, a channel controller 206, a power supply unit 207, routing information. DB 208, terminal information DB 209, channel information DB 210, and connection terminal 211 are provided.

  The relay antenna 201 and the relay transceiver 203 are used for transmission / reception of a radio signal for communication between the radio base stations 107 to form a relay radio channel. The access antenna 202 and the access transceiver 204 are used to transmit and receive radio signals for communication between the radio base station 107, the information collection terminal 108, and the network camera 109, and form an access radio channel. To do.

The routing control device 205 is used for routing control between radio base stations related to information transmitted from the information collection terminal 108 and the network camera 109, and bridge control between an access radio channel and a relay radio channel.
The routing control device 205 is connected to a connection terminal 211 that is connected to an existing communication network such as the public network 106. Accordingly, the routing control device 205 sends information transmitted from the information collection terminal 108 or the network camera 109 to the public network 106 via the connection terminal 211, and inputs information input from the public network 106 from the connection terminal 211. If necessary, the information can be relayed between the radio base stations and provided to the information collecting terminal 108 or the network camera 109 connected to each radio base station 107.

The channel control device 206 controls the relay radio channel formed by the relay transceiver 203 and the access radio channel formed by the access transceiver 204.
The power supply device 207 includes a storage battery, a voltage stabilization circuit, and the like, and supplies power to each circuit in the radio base station 107.
The routing information DB 208 is provided to hold and manage information related to routing paths between radio base stations. The terminal information DB 209 is provided to hold and manage information regarding each information collection terminal 108 and the network camera 109. The channel information DB 210 is provided in order to hold and manage information related to the radio channel used by the own station and other radio base stations 107.

By the way, when the environment monitoring system as shown in FIG. 1 is configured, wireless signals transmitted from a plurality of adjacent wireless base stations 107 and wireless signals transmitted from the information collecting terminal 108 or the network camera 109 are mutually connected. It is desirable to use a plurality of radio channels having different frequencies and the like so as not to interfere.
For example, in a 2.4 GHz band wireless LAN system typified by IEEE802.11b and a 5 GHz band wireless LAN system typified by IEEE802.11a, a maximum of four radio channels can be used. Also, no license is required to use this wireless channel.

Therefore, the environmental monitoring system shown in FIG. 1 is similar to the 2.4 GHz band wireless LAN system or the 5 GHz band wireless LAN system, and has a maximum of four wireless channels CH (A), CH (B), CH (C), CH ( Assume that D) can be used.
As a specific example, four available radio channels CH (A), CH (B), CH (C), and CH (D) are assigned to the radio base stations 107 (1), 107 (2), 107 ( The results assigned to 3), 107 (4) and 107 (5) are shown in FIG.

  Each radio base station 107 has at least one radio channel for relay and one radio channel for access, but in order to avoid interference between the radio signal for relay and the radio signal for access, the same It is necessary to assign radio channels so that the radio base station relay radio channel and the access radio channel have different frequencies. However, since the number of usable channels is finite, an optimum channel assignment is required.

1 and 3, since the connection terminal 211 of the radio base station 107 (1) is connected to the public network 106, the radio base station 107 (1) is treated as the root radio base station at the reference position, and the channel Make an assignment. It is assumed that the network topology is determined as shown in FIG. 1 before channel assignment.
The process performed to perform the optimal channel assignment is shown in FIG. The process shown in FIG. 4 will be described below.

  In step S41, the number of branches of the radio base station 107 (1) that is the root radio base station is determined. The maximum value of the number of branches is preferably about ½ of the total number of channels. This is because all radio base stations have different channels for access and relay, so the number of branches is equivalent to the number of relay paths, and the average frequency utilization is to assign the same number of channels for access. This is because the efficiency is increased.

In step S42, different radio channels are allocated to the two relay systems and one access system of the radio base station 107 (1), which is the root radio base station. In the example shown in FIG.
Radio channels CH (A) and CH (B) are assigned to the two relay systems of the radio base station 107 (1), and the radio channel CH (C) is assigned to one access system.

  In step S43, the access channel of the root radio base station is connected to the access system of the radio base stations 107 (2) and 107 (5) located one hop adjacent to the radio base station 107 (1) that is the root radio base station. Assign different radio channels. However, the remaining channels (in this case, the radio channel CH (D) not used by the root radio base station) are radio base stations (here, the root base station 107) that is one hop higher (higher is closer to the root base station). To the wireless base station with the largest number of wireless base stations connected (other than the wireless base station 107 (2) here). The access system of the other radio base station 107 (5) includes the same radio as the relay channel between the radio base station 107 (1) that is the root radio base station and the radio base station 107 (2) that is adjacent to one hop. Assign channels. In the example of FIG. 3, the radio channel CH (A) is assigned to the access system of the radio base station 107 (5).

In step S44, the radio base station 107 (1) is connected to the relay system of the radio base stations 107 (2) and 107 (5) located at one hop adjacent to the radio base station 107 (1) as the root radio base station. Assign an unused radio channel for connection. In this example, the same radio channel as that used for the access of the 1-hop higher base station is allocated.
In step S45, the access channel of the radio base station 107 (3) located two hops lower than the root base station is determined. A channel that is not used by the radio base station 107 (2), which is a one-hop higher base station (an adjacent base station close to the root base station), is assigned to this access system. In the example of FIG. 3, the radio channel CH (B) is assigned to the access system of the radio base station 107 (3).

  In step S46, a channel is assigned to the relay system on the lower side of the radio base station 107 (3) located two hops below the root base station. Since the upper-side relay channel for connecting to the upper adjacent base station is determined by assignment to the upper adjacent base station, the lower-side relay system of the radio base station 107 (3) is the upper adjacent base station. The same radio channel CH (D) as the access system of the radio base station 107 (2) is allocated.

In step S47, the access channel of the radio base station 107 (4) located 3 hops below the root base station is determined. As in steps S43 and S45, a radio channel that is not used by the radio base station 107 (3), which is an upper adjacent base station, is allocated to this access system.
In step S48, as in steps S44 and S46, the same radio channel as the access channel CH (B) of the radio base station 107 (3), which is a 1-hop higher adjacent base station, is assigned to the radio base station 107 (4). Assign to lower relay system.

  When the number of radio base stations further increases, the radio channel can be automatically allocated to all radio base stations by further repeating the same processing as steps S47 and S48 in FIG. Therefore, even when the number of usable radio channels is limited, the number of radio base stations 107 constituting the environmental monitoring system can be increased as necessary. Even in insufficient places, it is possible to flexibly deal with environmental information collection and illegal dumping monitoring.

  Further, by assigning the relay channel and the access channel differently between adjacent radio base stations, it is possible to effectively use a finite frequency resource and reduce the transmission delay due to the relay. The effect of reducing the transmission delay is that one radio channel is shared by a plurality of radio apparatuses as in the case of using the CSMA / CA method adopted in IEEE802.11a / b for access control of radio base stations. This becomes prominent in the access method.

  Each information collection terminal 108 and network camera 109 constituting the environmental monitoring system incorporate a wireless communication interface for transmitting the collected information and the information of the captured video as wireless signals. A radio signal transmitted from the information collecting terminal 108 and the network camera 109 is received by one of the radio base stations 107 and relayed as necessary, and is transmitted to the management server 104 via the radio base station 107 (1) and the public network 106. Is transmitted.

  A configuration example of each information collection terminal 108 is shown in FIG. Referring to FIG. 5, the information collection terminal 108 includes a central processing unit 501, a voice input unit 502, a text input unit 503, an image / video input unit 504, an environmental information sensor 505, an information display unit 506, an information storage unit 507, and position information. An acquisition device 508, a wireless transmission / reception device 509, a transmission / reception antenna 510, and terminal control software 511 are provided.

A central processing unit (CPU) 501 controls the information collection terminal 108 according to terminal control software 511. The voice input device 502 detects a human voice using a predetermined microphone, converts it into a digital signal, and performs voice recognition for operation input. The text input device 503 generates character string information in accordance with an input from a keyboard or the like.
The image / video input device 504 is used to input video and image information captured by a predetermined television camera. The environmental information sensor 505 has a function of detecting environmental information such as temperature, humidity, and the concentration of a certain component in the air, the concentration of a certain component in water, the concentration of a certain component in soil, vibration, and noise.

  The information display device 506 is used to display collected environmental information and the like. The information storage device 507 is used for storing collected environmental information and the like. The position information acquisition device 508 has a function of detecting the current position (installation position) of the information collection terminal 108 using a GPS (Global Positioning System) receiver or the like. The wireless transmission / reception device 509 and the transmission / reception antenna 510 are used to perform wireless communication with the wireless base station 107.

Information collection using the environmental information sensor 505 and the image / video input device 504 is performed, for example, periodically or in accordance with an instruction from the management server 104. The collected information can be operated by an environment investigator by directly operating the information collection terminal 108 on site.
For example, the central processing unit 501 realizes the following operation according to the operation input of the environment investigator. That is, the environmental information sensor 505 collects measurement data such as the concentration, temperature, and humidity of the target component in the air, water, and soil and saves it in the information storage device 507 or displays it on the information display device 506. Can be.

In addition, the voice input device 502 and the image / video input device 504 collect voice data and image / video data related to the environment by the input operation of the environment investigator, and the environment investigator uses the text input device 503 and the voice input device 502. It is also possible to add text data such as a comment or voice data input by itself and transmit it to the management server 104.
The central processing unit 501 automatically stores the collected environment information in the information storage device 507 in association with the position information obtained by the position information acquisition device 508. The position information is also added to the information transmitted to the management server 104. For this reason, mapping of the acquired environmental information to geographical information and centralized management become easy.

When a television camera is connected to the image / video input device 504 of each information collection terminal 108, it is not necessary to provide an independent network camera 109.
As described above, by using the environmental monitoring system of this form, it is possible to realize collection of environmental information and remote monitoring of illegal dumping even in an area where existing communication facilities are not sufficiently developed. In addition, it can be used to collect information on the disaster area even in the event of a disaster where the use of communication facilities is difficult.

(Second Embodiment)
One embodiment of the environmental monitoring system of the present invention will be described with reference to FIGS. This form corresponds to claim 2. FIG. 6 is a sequence diagram showing a connection procedure of the information collecting terminal. FIG. 7 is a schematic diagram showing a configuration example of a communication frame used in the connection procedure.
This form is a modification of the first embodiment. Since the basic configuration and operation of the system are the same as those in the first embodiment, only the changed part will be described.

  In this mode, the management server 104 manages the address of the network interface of the information collection terminal 108 that can participate in the communication network formed by this system, and the management server 104 stores all information about each information collection terminal 108. Delivered to the radio base station 107. When receiving a connection request from each information collection terminal 108, each wireless base station 107 approves the connection only when the address of the network interface matches information registered in advance.

  Also, each time a connection is established, the wireless base station 107 assigns a different network address to the information collecting terminal 108, and uses the management server 104 and other wireless information as a table indicating the correspondence between the network address and the network interface address. Delivered to the base station 107. As a result, the information collection terminal 108 that can participate in the communication network of the system can be filtered, and unauthorized terminal access can be eliminated.

In order to perform such control, a connection procedure as shown in FIG. 6 is performed. In this connection procedure, communication for connection is performed using a communication frame having a configuration as shown in FIG.
In step S60, the management server 104 registers the network interface address uniquely assigned to the network interface of each terminal (108, 109) permitted to participate in the communication network of the system in the terminal information DB 101 according to an input instruction from the operator, for example. To do.

In step S <b> 61, the management server 104 distributes the network interface address information of each terminal registered in the terminal information DB 101 to all the radio base stations 107.
Each radio base station 107 periodically transmits a terminal access control signal to all terminals (S62).

When the information collection terminal 108 that has not yet participated in the communication network of the system receives a control signal periodically transmitted from the radio base station 107, a communication frame for connection request (communication frame (1) in FIG. 7). Is transmitted to the radio base station 107. As shown in FIG. 7, this connection request includes the requesting terminal name and the network interface address.
The communication frame (1) for connection request is transmitted in a state encrypted with the common key of the environmental monitoring system. Furthermore, a function that obtains a hash value of the communication frame using a hash function that is said to be impossible to reproduce once encrypted is provided as an optional function. As a result, it is possible to control so that the response frame is not sent unless the hash value of the decrypted communication frame matches the original hash value.

  The radio base station 107 that has received the connection request sends a response frame of the request source only when the address of the network interface included in the connection request matches the registered content, that is, when access of the request source is permitted. It transmits to the information collection terminal 108 (S64). This response frame includes a network address newly assigned to the request source as in the communication frame (2) shown in FIG.

In addition, the radio base station 107 uses the information indicating the correspondence relationship between the terminal name and the network interface address of the terminal approved to participate in the communication network of this system in step S64 as the correspondence table and other information as a correspondence table. It transmits with respect to the wireless base station 107 and the management server 104 (S65).
When the management server 104 receives the correspondence table transmitted by the radio base station 107 in step S65, the management server 104 newly assigns the contents, that is, the terminal name and the network interface address of the terminal approved to participate in the communication network of this system. Information indicating the correspondence with the network address is stored in the terminal information DB 101 of the own station (S66).

  Further, the other radio base station 107 that has received the correspondence table transmitted by the radio base station 107 in step S65 updates the contents of the terminal information DB 209 managed by the own station according to the received correspondence table (S67). Further, the radio base station 107 gives the contents of the received correspondence table to the terminals (108, 109) existing in the area where radio communication with the own station can be performed, that is, the terminals approved to participate in the communication network of this system. The terminal information updated according to the correspondence between the terminal name and the network interface address and the newly assigned network address is transmitted (S68).

The wireless base station 107 that has transmitted the correspondence table also updates the terminal information of the terminal that has approved the participation in the communication network of this system, the terminal information updated according to the correspondence relationship between the network interface address and the newly assigned network address. Is transmitted to the terminals (108, 109) existing in the area where wireless communication with the own station is possible (S69).
By performing the control as described above, information collection terminals that can participate in the network can be filtered by the address of the network interface, and unauthorized terminal access can be eliminated.

(Third embodiment)
One embodiment of the environmental monitoring system of the present invention will be described with reference to FIGS. This form corresponds to claim 3. FIG. 8 is a sequence diagram showing a communication procedure when data is transferred between information collection terminals. FIG. 9 is a time chart showing a specific example of encryption.

This form is a modification of the first embodiment and the second embodiment. Since the basic configuration and operation of the system are the same as those in the first embodiment, only the changed part will be described.
In this form, when the wireless base station 107 approves the connection of the information collecting terminal 108 and assigns a network address in step S64 of FIG. 6, it is unique for each session (a state in which a connection with a secured authorization is maintained). Is provided to the information collecting terminal 108. The information collection terminal 108 performs communication encrypted using a given encryption key.

Each information collection terminal 108 and each radio base station 107 encrypts and transmits information to be transmitted using a secret key that is uniquely given to each information collection terminal 108 and receives data using a public key that is paired with the secret key. Decrypt.
FIG. 8 shows a communication procedure when data is transferred between two information collection terminals (transmission source, destination) 108 existing in different wireless communication areas formed by different wireless base stations 107. The procedure shown in FIG. 8 will be described below.

The management server 104 periodically changes the secret key of each radio base station 107 and the public key used for decrypting transmission data from other radio base stations 107, and periodically updates the information for each Transmit to the radio base station 107 (S81).
The wireless base station 107 forming the wireless communication area of the transmission source information collection terminal 108 transmits the network address and the terminal-specific secret key to the information collection terminal 108 that has approved the connection (S82). Also, the transmission source radio base station 107 stores the public key for decrypting the data encrypted with the terminal-specific secret key and the secret key in the terminal information DB 209 of the own station (S83).

The transmission source information collection terminal 108 encrypts data to be transmitted using a given encryption key (secret key), and transmits the encrypted data to the destination information collection terminal 108 (S84). .
The transmitting-side radio base station 107 that has received the encrypted data from the source information collecting terminal 108 forms a radio communication area where the destination information collecting terminal 108 exists based on the contents of the terminal information DB 209 of the own station. The destination radio base station 107 is searched. In addition, the transmission-side radio base station 107 re-encrypts the data transmitted by the transmission-source information collection terminal 108 using the secret key assigned to the transmission-side radio base station 107 (S85). Then, the re-encrypted data is transmitted to the destination radio base station 107 (S86).

Further, the transmitting-side radio base station 107 further encrypts a public key for decrypting the encrypted data from the transmission source terminal using a common encryption key between the radio base stations, and the destination-side radio base station It transmits to 107 (S87).
The destination radio base station 107 decrypts the re-encrypted data transmitted from the radio base station 107 on the transmission side using a public key that is paired with a secret key unique to the base station, and transmits the information collecting terminal of the transmission source The data is converted into encrypted data transmitted by 108 (S88). Then, the converted encrypted data is transmitted to the destination information collection terminal 108 (S89).

Further, the destination-side radio base station 107 transmits a public key for decrypting the encrypted data transmitted by the source information collection terminal 108 to the destination information collection terminal 108 (S8A).
The destination information collection terminal 108 decrypts the encrypted data transmitted from the destination-side radio base station 107 using a public key paired with the secret key assigned to the source information collection terminal 108, Restore the transmitted data.

As described above, a unique encryption key is given to the information collection terminal for each session between the base station and the terminal, and the information collection terminal communicates data encrypted using the given encryption key, and receives the destination address to be received. The information collection terminal can perform communication with higher secrecy by decrypting with the public key that is paired with the unique encryption key.
A specific example of encryption is shown in FIG. The system can be simplified by making the secret key used for encryption the same as the public key used for decryption.

In the example shown in FIG. 9, the raw data a (t) of the transmission information is encoded data of ± 1, and the encryption key b (t) has a finite length and has the same cycle as the raw data. Is a categorization sequence. Here, the encrypted data c (t) is expressed by the following equation.
c (t) = a (t) × b (t)
Further, by multiplying the encrypted data c (t) by b (t) once again, it can be decrypted as the following equation.
a (t) = c (t) × b (t) = a (t) × b (t) ² = a (t) × 1
(Fourth embodiment)
One embodiment of the environmental monitoring system of the present invention will be described with reference to FIGS. This form corresponds to claim 4.

FIG. 10 is a schematic diagram showing an example of the minimum communication frame configuration of the access control signal. FIG. 11 is a flowchart illustrating an example of control of the information collection terminal. FIG. 12 is a graph showing an example of detecting an access control signal. FIG. 13 is a schematic diagram illustrating a discrimination example of the detection result of the access control signal.
This form is a modification of the first embodiment. Of course, it can be combined with other embodiments. Since the basic configuration and operation of the system are the same as those in the first embodiment, only the changed part will be described.

In this mode, when the information collection terminal 108 establishes a connection with the radio base station 107, an optimum radio base station is selected based on the reception strength and the number of other information collection terminals 108 that are already connected. And control to connect.
For example, the control signal transmitted by the radio base station 107 in step S62 in FIG. 6 is an access control signal used for control for a terminal such as the information collection terminal 108 to access the radio base station 107. For example, as shown in FIG. 10, this access control signal includes at least a command ID indicating the type of instruction, a base station ID for identifying the transmission source radio base station 107, and a transmission source radio base station 107. And the number of connected terminals (managing participation in the communication network).

The contents of control of the information collecting terminal 108 for connecting to the radio base station 107 are shown in FIG. The contents of the control shown in FIG. 11 will be described below.
In step S111, the information collection terminal 108 attempts to receive the access control signal transmitted from each radio base station 107 and detects the reception strength and the like, while directly detecting the reception strength and the like in the radio base station 107 included in this system. A wireless base station 107 capable of communication is searched.

As a result of this search, for example, a detection result as shown in FIG. 12 is obtained. In practice, as shown in FIG. 13, tabular information in which the IF (network interface) address of the wireless base station, the wireless channel, the reception strength, and the number of connected terminals are associated is obtained as a search result.
In step S112, the information collection terminal 108 compares the reception strength of the access control signal received on each channel with a predetermined threshold (see FIG. 12), and determines whether the reception strength is equal to or higher than the threshold. For example, in FIG. 13, the hatched portion represents a signal whose reception intensity is greater than or equal to a threshold value.

In step S113, the information collection terminal 108 selects the wireless base station 107 having the smallest number of connected terminals among the wireless base stations 107 that have transmitted a signal having a reception strength equal to or higher than the threshold. In the example of FIG. 13, the radio base station 107 whose IF address is (BS000009) is selected.
In step S114, the information collection terminal 108 makes a network address acquisition request for connection to the specific radio base station 107 (BS000009) selected in step S113.

In step S115, the information collection terminal 108 acquires information transmitted from the requested wireless base station 107 (BS000009), that is, information on the network address assigned to the own station and other information collection terminals 108 that can be connected.
By performing the control as described above, when the information collection terminal 108 requests connection to the wireless base station 107, the connection request is made by selecting the optimum wireless base station from the viewpoint of reception strength and channel usage. Can do.

(Fifth embodiment)
One embodiment of the environmental monitoring system of the present invention will be described with reference to FIG. 14, FIG. 15 and FIG. This form corresponds to claim 5. FIG. 14 is a schematic diagram illustrating a discrimination example of the detection result of the relay system control signal. FIG. 15 is a flowchart showing an example of system control. FIG. 19 is a graph showing an example of detection of a relay system control signal.

This form is a modification of the first embodiment. Of course, it can be combined with other embodiments. Since the basic configuration and operation of the system are the same as those in the first embodiment, only the changed part will be described.
In this mode, when a new radio base station 107 joins the communication network of this system and establishes a connection with another radio base station 107, the reception strength and the other radio base station 107 already connected are connected. Based on the number, control is performed so as to select and connect another optimal radio base station.

That is, control as shown in FIG. 15 is performed. The contents of the process shown in FIG. 15 will be described below.
In step S141, the radio base station 107 that intends to newly join the communication network performs inter-base station communication that all other radio base stations 107 that have already joined regularly transmit using a relay radio channel. The base station 107 searches for a receivable radio base station 107 while measuring the reception intensity and the like.

As a result of this search, information associating the IF address of the radio base station, the radio channel, the reception intensity, and the number of known connection stations is obtained for each control signal as shown in FIG. In this example, since each radio base station 107 has two relay radio channels, two signals are detected for each base station.
In step S142, the result obtained in S141 is selected with a reception intensity equal to or higher than a predetermined threshold. For example, in FIG. 14, the hatched portion represents a signal whose reception intensity is equal to or greater than a threshold value.

In step S143, one signal of the base station with the smallest number of connected base stations is selected from the radio base stations 107 that have transmitted a signal having a reception strength equal to or higher than the threshold. In the example of FIG. 14, the signal of the radio channel CH (C) of the radio base station 107 whose IF address is (BS000002) is selected.
In step S144, the radio base station 107 that intends to newly join the communication network makes a connection request to the network to the connection-destination radio base station 107 selected in S143.

Receiving the connection request to the network, the wireless base station 107 inquires of the management server 104 whether the network interface address of the requesting wireless base station 107 is registered in the base station information DB 103 of the management server 104 (S145). ).
In this case, if the network interface address of the wireless base station 107 that requested the connection is registered, the management server 104 assigns a new network address, associates the network interface address, the network address, and the connection position with each other to the base station. Save in the station information DB 103 and update the record of the network topology (connection form). Further, the management server 104 transmits a network address distribution command to the wireless base station 107 requested to connect (S146).

  The wireless base station 107 requested to connect in S144 follows the network address distribution command from the management server 104 to the wireless base station 107 that is the connection request source, permits network connection, the network address, and the terminal in the network. Send information. The requesting radio base station 107 acquires the network address assigned to itself according to the information received from the connection-destination radio base station 107, and receives the base station of its own station from all other radio base stations 107. Information is transmitted by broadcast (S147).

When each of the other radio base stations 107 receives information broadcast from the requesting radio base station 107, the information of the newly added radio base station 107 is stored in the routing information DB 208 of each station according to the information. Update its contents.
By controlling as described above, when a new radio base station 107 is connected and the area is expanded, it is possible to select and connect the optimum radio base station from the viewpoint of reception strength and channel usage. .

(Sixth embodiment)
One embodiment of the environmental monitoring system of the present invention will be described with reference to FIG. This form corresponds to the sixth aspect. FIG. 16 is a block diagram illustrating a control example of the radio base station.
This form is a modification of the first embodiment. Of course, it can be combined with other embodiments. Since the basic configuration and operation of the system are the same as those in the first embodiment, only the changed part will be described.

  In this embodiment, when a plurality of communication frames from the network camera 109 and the information collection terminal 108 are received simultaneously, a predetermined process is performed, and then transmitted to another wireless base station 107 or the management server 104, the network camera 109 Control is performed so that packets are scheduled so that communication frames of audio information from the video and information collection terminal 108 are preferentially processed. As a result, the quality of video and audio signals with high real-time characteristics can be improved.

In this embodiment, each radio base station 107 includes a receiving device 1601, a buffer 1602, a scheduler 1603, and a transmitting device 1604 as shown in FIG.
The received packet received by the receiving device 1601 is temporarily stored on the buffer 1602, processed by the scheduler 1603, and then transmitted to the other radio base station 107 or the management server 104 through the transmitting device 1604.

The scheduler 1603 gives a higher priority to packets including information with high real-time properties such as video and audio than other packets, and changes the order of transmission processing.
In the example of FIG. 16, the packets P1, P2, P3, P4, P5, P6, P7, P8, P9, P10,... The arrangement order is changed according to the priority order, and the packets are arranged in the order of P1, P2, P3, P4, P5, P7, P6, P10, P8, P9,. That is, the arrangement is changed so that the video packets shown by hatching are arranged at regular intervals according to the packet size.

The transmission apparatus 1604 transmits each packet according to the scheduling of the scheduler 1603. As a result, the video packet receiving side can reproduce the video packet at regular intervals, so that it is possible to prevent video delay due to traffic concentration.
As described above, by performing scheduling so as to preferentially process video and audio packets, it is possible to improve video and audio communication quality in an environment monitoring system that handles various media information.

(Seventh embodiment)
One embodiment of the environmental monitoring system of the present invention will be described with reference to FIGS. 17 and 18. This form corresponds to the seventh aspect. FIG. 17 is a block diagram illustrating a configuration example of the system. FIG. 18 is a flowchart showing an example of the operation of the system.
This form is a modification of the first embodiment. Of course, it can be combined with other embodiments. Since the basic configuration and operation of the system are the same as those in the first embodiment, only the changed part will be described.

In this form, a device for providing environment information collected by the management server 104 from each information collection terminal 108 and network camera 109 to a previously registered user is added.
Referring to FIG. 17, this system includes an information disclosure server 1701, an environment information DB 1702, a user information DB 1703, a network 1704, and an information acquisition terminal 1705. In addition, although the elements shown in FIG. 1 are actually provided, the description is omitted in FIG.

  Various environment information acquired by the management server 104 is registered in the environment information DB 1702. The information disclosure server 1701 performs control for providing the environment information held in the environment information DB 1702 to the user. The user information DB 1703 holds and manages information (user ID, password, etc.) of users who are permitted to acquire environment information from this system. Each information acquisition terminal 1705 is a terminal used by a user to browse and download environmental information, and for example, a personal computer can be used.

When the user acquires environmental information from this system, the processing is performed in the procedure as shown in FIG. The process shown in FIG. 18 will be described below.
In step S181, the information acquisition terminal 1705 makes an access permission request to the information disclosure server 1701 in accordance with a user input operation, and logs in to the service.
In step S182, the information disclosure server 1701 performs user authentication by checking whether or not the password input by the user at the time of login matches that registered in the user information DB 1703.

In practice, the information disclosure server 1701 first determines a user password. Next, a part of the user information encrypted with the encryption key uniquely assigned to each user is transmitted from the information acquisition terminal 1705 to the information disclosure server 1701, and the encryption key and the user information are registered contents of the user information DB 1703. It is determined whether it matches.
In step S183, the information disclosure server 1701 presents a menu of environmental information that can be disclosed to the information acquisition terminal 1705 that has completed user authentication.

In step S184, according to the user's input operation, the information acquisition terminal 1705 selects the environment information to be browsed from among the environment information that can be disclosed.
In step S185, the information disclosure server 1701 presents a viewing fee and a download fee for the selected environment information.
In step S186, the information acquisition terminal 1705 performs electronic payment after the user confirms the viewing fee and the download fee.

In step S187, the information disclosure server 1701 presents the environmental information for which electronic payment has been completed to the information acquisition terminal 1705, and permits downloading of the environmental information as necessary.
Therefore, a user who has been permitted in advance can acquire the environment information collected by the management server 104.

It is a block diagram which shows the structural example of a system. It is a block diagram which shows the structural example of a wireless base station. It is a block diagram which shows the example of allocation of a radio channel. It is a flowchart which shows the allocation process of a radio channel. It is a block diagram which shows the structural example of an information collection terminal. It is a sequence diagram which shows the connection procedure of an information collection terminal. It is a schematic diagram which shows the structural example of the communication frame used in a connection procedure. It is a sequence diagram which shows the communication procedure in the case of transferring data between information collection terminals. It is a time chart which shows the specific example of encryption. It is a schematic diagram which shows the example of a minimum communication frame structure of an access control signal. It is a flowchart which shows the example of control of an information collection terminal. It is a graph which shows the example of a detection of an access control signal. It is a schematic diagram which shows the example of discrimination | determination of the detection result of an access control signal. It is a schematic diagram which shows the example of discrimination | determination of the detection result of a relay system control signal. It is a flowchart which shows the example of control of a system. It is a block diagram which shows the example of control of a radio base station. It is a block diagram which shows the structural example of a system. It is a flowchart which shows the operation example of a system. It is a graph which shows the example of a detection of a relay type | system | group control signal.

Explanation of symbols

101 Terminal information DB
102 Environmental Information DB
103 Base station information DB
DESCRIPTION OF SYMBOLS 104 Management server 105 Environmental information display apparatus 106 Public network 107 Wireless base station 108 Information collection terminal 109 Network camera 201 Relay antenna 202 Access antenna 203 Relay transceiver 204 Access transceiver 205 Routing controller 206 Channel controller 207 Power supply Supply device 208 Routing information DB
209 Terminal information DB
210 Channel information DB
211 Connection terminal 501 Central processing unit 502 Voice input device 503 Text input device 504 Image video input device 505 Environmental information sensor 506 Information display device 507 Information storage device 508 Location information acquisition device 509 Wireless transmission / reception device 510 Transmission / reception antenna 511 Terminal control software 1601 Reception Device 1602 Buffer 1603 Scheduler 1604 Transmission device 1701 Information disclosure server 1702 Environment information DB
1703 User information DB
1704 Network 1705 Information acquisition terminal

Claims (7)

Information collection terminal that collects at least one kind of environmental information obtained by measurement of temperature, humidity, air quality, water quality, soil quality, noise, vibration, etc. or bio-ecological survey, remote monitoring of illegal dumping, remote observation of natural environment A network camera that shoots video used for, for example, is connected to the information collection terminal and the network camera via a predetermined network, and manages the network camera and environmental information collected by the information collection terminal In an environmental monitoring system comprising a management server and at least one wireless base station that can be connected to a communication facility such as a public network or a LAN,
The information collection terminal includes an environmental information sensor for detecting at least one of temperature, humidity, air quality, water quality, soil quality, noise, and vibration as part of environmental information, and a user's voice for operation. Alternatively, according to the input to the operation information input device, the position information acquisition device, and the operation information input device that accepts input of character information, image or video information is collected as part of the environment information, and the position information acquisition device In order to communicate between the radio base station, an information recording device that records the acquired positional information and the acquired environmental information in association with each other, an information display device that displays the environmental information and positional information in association with each other With a wireless transceiver
The network camera is equipped with a wireless transmitting / receiving device for communicating with the wireless base station,
The management server includes an environment information database that manages environment information transmitted from the information collection terminal, a terminal information database that manages information about the information collection terminal, and base station information that manages information about the radio base station Connected with a database, equipped with a function to acquire and display video sent from the network camera and environmental information sent from the information collection terminal,
The wireless base station includes at least one first communication interface for connecting to a public network or a LAN, at least one second communication interface for performing wireless communication with the information collection terminal, and a relay. An environment monitoring system comprising: at least one third communication interface for wireless communication between wireless base stations. In the environmental monitoring system of claim 1,
The management server, when giving permission to use the communication network including the base station to the information collection terminal, registers the address of the network interface uniquely assigned to the information collection terminal in the terminal information database, Deliver information registered in the terminal information database to all available radio base stations,
The radio base station identifies a connection request from the information collection terminal based on the contents of the terminal information database distributed from the management server, and a network interface address uniquely assigned to the information collection terminal Approves the connection only when it is registered in the terminal information database, assigns a different network address to the information collection terminal every time a connection is established, and represents information indicating the correspondence between the network address and the address of the network interface And delivering to the management server and other radio base stations. In the environmental monitoring system of claim 2,
The wireless base station creates a unique encryption key and a decryption key for decrypting encrypted information in pairs for each session when approving the connection of the information collection terminal, Notifying the information collection terminal of an encryption key, storing the encryption key and the network address in association with each other in the terminal information database, and receiving the encrypted information An environment monitoring system characterized by notifying the decryption key each time and performing communication using a communication frame encrypted using an encryption key for each session in communication in a wireless section. In the environmental monitoring system of claim 2,
When the information collection terminal makes a connection request to the radio base station, each radio base station receives an access control signal periodically transmitted using the second communication interface, and the received access control signal The radio base station having a reception strength of 1 or more and a minimum number of other information collection terminals already connected is selected, and a connection request is made to the selected radio base station. Environmental monitoring system. In the environmental monitoring system of claim 1,
When the radio base station tries to join another communication base station that has already formed a communication network and participates in the communication network, each radio base station periodically uses the third communication interface. The base station communication control signal to be transmitted to the base station is received, the reception strength of the received base station communication control signal is equal to or higher than a predetermined value, and the number of other wireless base stations already connected is the smallest. An environment monitoring system characterized by selecting a base station and making a connection request to the selected radio base station. In the environmental monitoring system of claim 1,
When the radio base station receives communication frames from a plurality of the network cameras and information collecting terminals simultaneously, the radio base station processes the video and audio communication frames preferentially over the communication frames composed of other information. And transmitting to other radio base stations and management servers. In the environmental monitoring system of claim 1,
An environment monitoring system further comprising: an information disclosure server for providing environmental information collected by the management server to a specific user; and a user information database for managing information related to the information disclosure target user. .

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