JP4113764B2 - Communications system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication system that performs communication via a relay device such as an access point or a router.
[0002]
[Prior art]
Recently, due to advances in communication technology, mobile communication systems that can use the same network environment as a company even when away from home have been developed (see, for example, Patent Document 1). In this mobile communication system, when performing handoff processing in which the network to which the mobile body belongs is changed, a buffer of an appropriate size is allocated for the mobile body based on the service rank information. It becomes possible to continue the communication of the requested quality without being aware of the network to which it belongs.
[0003]
In communication via this mobile communication system or a general IP (Internet Protocol) network, an IP address is dynamically or statically assigned to each communication device such as a mobile. Considering a global address as this IP address, consideration is given to assigning a non-overlapping IP address to each communication device, and it is ensured that a packet can be reliably transmitted by simply specifying a destination IP address in the header of the packet. It is possible to reach a communication device corresponding to.
[0004]
[Patent Document 1]
Japanese Patent Laying-Open No. 2002-238067 (page 7-13, FIG. 1-24)
[0005]
[Problems to be solved by the invention]
By the way, the above-mentioned IP address is only assigned to each communication device so as not to overlap, and there is no relationship between the contents and the installation location of the communication device. For this reason, even if an attempt is made to communicate with a communication device such as an access point or router installed in a certain region or each terminal device in a LAN (Local Area Network) constructed including these devices, The IP addresses of these communication devices cannot be specified. On the other hand, by looking at the source IP address included in the header part of a packet received from another terminal device, the installation location of a communication device such as an access point to which the terminal device is connected is specified from this IP address. It is not possible. Thus, conventionally, there has been a problem that the installation location of the communication device cannot be specified from the IP address. For this reason, if you specify a location and try to send or receive information to or from a communication device installed at that location, if there are facilities or organizations that manage the installation location of the communication device, The procedure was complicated. In addition, since a communication device cannot be specified by location, there is a method of performing broadcast distribution to all devices. However, since broadcast distribution occupies that much network resource, it is not preferable.
[0006]
The present invention was created in view of the above points, and its purpose is to perform communication specifying the installation location of the communication device and to know the installation location of the communication device based on the address information. An object of the present invention is to provide a communication system.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, a communication system according to the present invention includes a plurality of communication devices connected to each other via a network and assigned fixed addresses, and one or a plurality of communication devices connected to any one of the communication devices. A terminal device, and correspondence information storage means for storing correspondence information between the location of the communication device and the address information of the communication device in a state that can be referred to by the terminal device. Thereby, by referring to the correspondence information stored in the correspondence information storage means, the relationship between the address information of the communication device and the installation location can be easily known.
[0008]
In addition, the terminal device described above refers to a communication device corresponding to the area specified by the area specifying unit by referring to the area specifying unit for specifying the communication destination area and the correspondence information stored in the corresponding information storage unit. It is desirable to include address acquisition means for acquiring the address information, and transmission processing means for creating and transmitting a packet having the address information acquired by the address acquisition means as the transmission destination address. Thereby, it is possible to perform communication specifying the installation location of the communication device.
[0009]
In addition, it is desirable that the transmission processing unit described above creates a multicast distribution packet for a terminal device connected to a communication device specified by a transmission destination address. As a result, information can be transmitted / received to / from a terminal device connected to a communication device installed at a specific location, and network resources can be used more effectively than when broadcast distribution is performed.
[0010]
In addition, the terminal device described above refers to reception processing means for receiving a packet sent from a communication device other than the communication device to which the device is connected, and correspondence information stored in the correspondence information storage means, Based on the transmission source address included in the packet received by the reception processing unit, a region determination unit that determines the installation location of the communication device corresponding to the transmission source address, and the installation location of the communication device determined by the region determination unit It is desirable to include processing means for performing processing according to the above. This makes it possible to perform processing such as selecting a packet to be processed only by examining the source address included in the received packet, and it is easy to obtain only information corresponding to a specific region.
[0011]
The terminal device described above is mounted on a vehicle, and the communication device is preferably an access point that is wirelessly connected to a terminal device mounted on a vehicle traveling in a predetermined communication area. This makes it possible to distribute information multicast to each terminal device connected to the access point, and to handle information received from any of these terminal devices separately from information received from other terminal devices. Become.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a communication system according to an embodiment to which the present invention is applied will be described with reference to the drawings.
FIG. 1 is a diagram illustrating an overview of a communication system according to an embodiment. As shown in FIG. 1, the communication system of this embodiment includes a network segment 100, a plurality of access points A and B, and a trunk line 200 in which these are connected to each other.
[0013]
The network segment 100 is a global network segment, and includes, for example, the Internet and other wide area networks.
The access point A is a wireless LAN relay device installed in the area A, and a LAN is formed including an in-vehicle terminal device (described later) mounted on a vehicle traveling in the area A. This access point A has a fixed IP address. In addition, this IP address is a global address that does not overlap within the communication system, and if a packet in which this IP address is set as a transmission destination address is transmitted to the network segment 100 or the trunk line 200, it must be accessed unless there is a communication abnormality. It is transmitted to point A.
[0014]
Similarly, the access point B is a wireless LAN relay device installed in the region B, and a LAN is formed including in-vehicle terminal devices mounted on vehicles traveling in the region B. The access point B has a fixed IP address as a global address.
[0015]
In this embodiment, each access point A, B is connected to a dynamic host (DHCP) with respect to an in-vehicle terminal device installed in a vehicle traveling in the corresponding area, a terminal device installed in each store in the corresponding area, or the like. A private IP address that operates as a Configuration Protocol server and is not duplicated is assigned to these in-vehicle terminal devices. When a packet is transmitted from the in-vehicle terminal device or the like to the trunk line 200 via the access point, the source IP address in the packet is rewritten from the private IP address to the global IP address of the access point at the access point.
[0016]
FIG. 2 is a diagram showing a detailed configuration of the in-vehicle terminal device 10 mounted on the vehicle a traveling in the area A corresponding to the access point A. It is assumed that an in-vehicle terminal device having the same configuration is mounted on each of the vehicles b1, b2, and b3 traveling in the region B corresponding to the access point B.
[0017]
As shown in FIG. 2, the in-vehicle terminal device 10 mounted on the vehicle a includes a terminal control unit 11, an IP address table storage unit 12, a transmission unit 13, a reception unit 14, and an antenna switching unit 15. . The in-vehicle terminal device 10 is connected to a GPS device 30 that detects a vehicle position.
[0018]
The terminal control unit 11 controls the entirety of the in-vehicle terminal device 10 to perform packet transmission / reception processing and perform predetermined application processing. For this purpose, the terminal control unit 11 includes an application processing unit 20, an address acquisition unit 21, a packet transmission processing unit 23, a packet reception processing unit 24, and an area determination unit 25.
[0019]
The application processing unit 20 performs application processing in order to provide a predetermined service to the user. For example, the application processing unit 20 requests transmission of specific information to a vehicle traveling in another area B, or when specific information is sent from each vehicle in the area B in response to this request. This is received and a predetermined process is performed.
[0020]
The address acquisition unit 21 specifies an IP address corresponding to the designated area when the application processing unit 20 outputs a request for information in which the area is designated. The IP address table storage unit 12 connected to the terminal control unit 11 stores correspondence information between IP addresses of various communication devices including the access points A and B and the installation locations of the communication devices in a table format. The address acquisition unit 21 acquires the IP address corresponding to the designated area by referring to the correspondence information. For example, the address acquisition unit 21 can acquire the IP address of the access point B installed in the region B by designating the region B.
[0021]
The packet transmission processing unit 23 creates a packet that contains the request for information output from the application processing unit 20. In the storage area of the transmission destination IP address of this packet, the IP address of the communication apparatus acquired by the address acquisition unit 21 is stored. The packet created in this way is transmitted from the antenna 17 via the antenna switching unit 15 from the transmission unit 13. A packet transmitted from the in-vehicle terminal device 10 mounted on the vehicle a is sent to the access point A, and is sent to the communication device specified by the destination IP address in the packet via the access point A.
[0022]
Further, the packet addressed to the in-vehicle terminal device 10 of the vehicle a sent to the access point A via the trunk line 200 is received by the receiving unit 14 via the antenna switching unit 15 after reaching the antenna 17. The packet reception processing unit 24 performs this series of packet reception processing, and extracts a transmission source IP address and reception target information included in the received packet.
[0023]
Based on the transmission source IP address extracted from the received packet by the packet reception processing unit 24, the region determination unit 25 determines the installation location of the communication apparatus that has transmitted this packet. Specifically, the area determination unit 25 refers to the correspondence information stored in the IP address table storage unit 12 to identify the installation location of the communication device corresponding to the transmission source IP address. For example, when a packet is sent from the access point B, the area B where the access point B is installed is specified. In this way, when the installation location of the communication device that is the transmission source of the packet is specified, the application processing unit 20 can perform different processes depending on the installation location.
[0024]
Various network devices included in the access points A and B and the network segment 100 described above correspond to communication devices. The in-vehicle terminal device 10 corresponds to the terminal device, and the IP address table storage unit 12 corresponds to the correspondence information storage unit. The application processing unit 20 is an area identification unit, a processing unit, an address acquisition unit 21 is an address acquisition unit, a packet transmission processing unit 23 is a transmission processing unit, a packet reception processing unit 24 is a reception processing unit, and an area determination unit 25 is Each corresponds to a region determination means.
[0025]
The communication system of the present embodiment has such a configuration, and the operation thereof will be described next.
FIG. 3 is a diagram showing a local community network formed in the region B corresponding to the access point B. As shown in FIG. For example, in region B, a gourmet net B1, a shortcut net B2, a ramen shop net B3, and a traffic jam net B4 are formed. The gourmet net B1 is a network that provides community information regarding restaurants that are concentrated in a specific place in the region B, and is connected to a fixed terminal device installed in each restaurant. The shortcut network B2 is a network that provides shortcut information. When a shortcut to the main line is detected directly between a plurality of vehicles or via the access point B, the in-vehicle terminal devices 10 mounted on the plurality of vehicles are mutually connected. To form this network. The ramen shop net B3 is a network that provides community information regarding ramen shops concentrated along a predetermined road, and is connected to fixed terminal devices installed in each ramen shop. The traffic jam network B4 is a network that provides traffic jam information, and when a traffic jam is detected between a plurality of vehicles directly or via the access point B, the in-vehicle terminal devices 10 mounted on the plurality of vehicles are connected to each other. This network is formed.
[0026]
FIG. 4 is a diagram illustrating an outline of an operation of searching for a community network formed in the region B by the vehicle a traveling in the region A. FIG. 5 is a flowchart showing an operation procedure of the in-vehicle terminal device 10 that searches for community information.
The application processing unit 20 in the terminal control unit 11 of the vehicle “a” determines whether or not there is a transmission request for a specific area (step 100). repeat. Further, when a transmission request for an inquiry for searching for a community network in the region B is made by the user, an affirmative determination is made in the determination of step 100, and then the address acquisition unit 21 stores the IP address table storage unit 12. By examining the stored correspondence information, the IP address of the access point B corresponding to the region B is acquired (step 101).
[0027]
Next, the packet transmission processing unit 23 creates a packet including an inquiry about the community network together with the header part designating the acquired IP address as the transmission destination IP address and the multicast delivery (step 102). The transmission unit 13 transmits this packet from the antenna 17. The packet transmitted from the antenna 17 reaches the access point B via the access point A, and is installed in the in-vehicle terminal device 10 or the store of each vehicle in the region B from the access point B as shown in FIG. Multicast distribution is made to the terminal device that has been sent (step 103).
[0028]
In this way, the presence or absence of the community network and the contents are inquired from the vehicle a traveling in the region A to the in-vehicle terminal device 10 of each vehicle in the region B or the terminal device installed in the store. Various types of community information corresponding to the region B desired to be obtained are sent back.
[0029]
FIG. 6 is a flowchart showing an operation procedure for receiving community information sent back from the in-vehicle terminal device 10 in the region B in response to an inquiry from the vehicle a. After multicast delivery of the inquiry packet from the vehicle a, the packet reception processing unit 24 in the in-vehicle terminal device 10 determines whether or not the packet has been received (step 110), and if not received, it is negative. Make a decision and repeat this decision. When a packet is received, an affirmative determination is made in step 110, and then the packet reception processing unit 24 extracts the source IP address from the header part of the received packet (step 111).
[0030]
Next, the region determination unit 25 determines the region corresponding to the transmission source IP address by examining the correspondence information stored in the IP address table storage unit 12 (step 112). The transmission source IP address included in the header part of the packet transmitted via the access point B from a vehicle or the like traveling in the region B is for the in-vehicle terminal device 10 of each vehicle when passing through the access point B. Since the private address has been rewritten to the global address of the access point B, when a packet transmitted from a vehicle or the like traveling in the region B is received, it is determined that the packet is transmitted from the region B Is done. In this case, an affirmative determination is made in the determination of step 113, and then the packet receiving unit 24 extracts community information included in the received packet, and the application processing unit 20 acquires the extracted community information. (Step 114). On the other hand, if the packet is transmitted from a region other than region B, a negative determination is made in the determination in step 113, and the packet reception processing unit 24 discards the packet (step 115). In the operation procedure shown in FIG. 6, all the packets transmitted from other than the region B are discarded, but in actuality, processing according to the content of the packet is performed.
[0031]
Next, the application processing unit 20 determines whether or not a predetermined time has elapsed since the inquiry packet was transmitted (step 116). If the predetermined time has not elapsed, a negative determination is made and the operations after step 110 are performed. repeat. If the predetermined time has elapsed, the application processing unit 20 analyzes the community information acquired so far (step 117).
[0032]
FIG. 7 is a diagram illustrating a result of analyzing community information. As shown in FIG. 7, when it is found as a result of the analysis that there are four community networks in the region B, the contents are displayed on a display device (not shown). The user can know the names of the four community networks by looking at the screen, and if necessary, select one of them and instruct information display to know more detailed contents. Can do.
[0033]
FIG. 8 is a diagram illustrating an outline of a communication state when the vehicle a enters the area B. As described above, since the vehicle a acquires information on the community network existing in the region B while traveling toward the region B, the vehicle a enters the region B at the same time (not necessarily at the same time). No), it becomes possible to access the community network that the vehicle wishes to connect to. In addition, this access method may be such that the vehicle-mounted terminal devices 10 mounted on the vehicle communicate with each other via the access point B in addition to performing vehicle-to-vehicle communication by direct wireless connection.
[0034]
As described above, in the communication system according to the present embodiment, by referring to the correspondence information stored in the IP address table storage unit 12, it is possible to perform communication specifying the installation location of a communication device such as an access point. At the same time, based on the IP address included in the received packet, the installation location of the communication device such as the access point that transmitted the packet can be known. In particular, it is possible to perform processing such as selecting a packet to be processed simply by examining the source IP address included in the received packet, and obtaining only information corresponding to a specific area (for example, community information). Becomes easy.
[0035]
In addition, it is possible to specify an IP address of an access point by designating a location (region) and transmit a packet to the access point. Therefore, the in-vehicle terminal device of each vehicle wirelessly connected to the access point 10 or a terminal device installed in each store or the like can be multicast-distributed to the terminal device, and the network resource is not limited to the case where the packet is broadcast-distributed to each terminal device without being limited to the region B. Effective use can be achieved by reducing wasteful use.
[0036]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. In the above-described embodiment, the case where the in-vehicle terminal device or the like of each vehicle is connected by wireless communication via an access point has been considered, but the present invention is also applied to the case where the terminal device is connected via a wired line. Can do. For example, a LAN connection port may be provided in a company or public facility, and a personal computer carried by the user may be cable-connected as necessary.
[0037]
In the above-described embodiment, an access point is considered as a communication device to which a fixed IP address is allocated. However, a fixed IP address is allocated to a router or other communication device, and correspondence information about these is stored in an IP address table. You may make it store in the part 12. FIG.
[0038]
Further, in the above-described embodiment, the IP address table storage unit 12 is provided in each in-vehicle terminal device 10, but the IP address table storage unit is provided in a place other than the in-vehicle terminal device 10 such as an access point. Also good.
In the above-described embodiment, the IP address has been described. However, for a network using an address other than the IP address, correspondence information indicating the relationship between the address and the installation location of the communication device should be created and managed. That's fine.
[0039]
【The invention's effect】
As described above, according to the present invention, the relationship between the address information of the communication device and the installation location can be easily known by referring to the correspondence information stored in the correspondence information storage means.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an overview of a communication system according to an embodiment.
FIG. 2 is a diagram showing a detailed configuration of an in-vehicle terminal device mounted on a vehicle a traveling in a region A corresponding to an access point A.
FIG. 3 is a diagram showing a local community network formed in an area B corresponding to an access point B;
FIG. 4 is a diagram showing an outline of an operation of searching for a community network formed in a region B by a vehicle a traveling in the region A.
FIG. 5 is a flowchart showing an operation procedure of the in-vehicle terminal device that searches for community information.
FIG. 6 is a flowchart showing an operation procedure for receiving community information sent back from an in-vehicle terminal device or the like in area B in response to an inquiry from vehicle a.
FIG. 7 is a diagram illustrating a result of analyzing community information.
FIG. 8 is a diagram showing an outline of a communication state when a vehicle a enters a region B.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 In-vehicle terminal device 11 Terminal control part 12 IP address table storage part 13 Transmission part 14 Reception part 15 Antenna switching part 17 Antenna 20 Application processing part 21 Address acquisition part 23 Packet transmission processing part 24 Packet reception processing part 25 Area determination part 30 GPS apparatus

Claims (4)

A plurality of communication devices connected to each other via a network and assigned fixed addresses;
One or more terminal devices connected to any of the communication devices;
Correspondence information storage means in which correspondence information between the installation location of the communication device and address information of the communication device is stored in a state that can be referred to by the terminal device , and
The terminal device
A reception processing means for receiving a packet sent from the communication device other than the communication device to which the device is connected;
Based on the transmission source address included in the packet received by the reception processing unit by referring to the correspondence information stored in the correspondence information storage unit, the communication device installation location corresponding to the transmission source address An area determination means for determining
Processing means for performing processing according to the installation location of the communication device determined by the area determination means;
A communication system comprising: In claim 1,
The terminal device
An area identification means for identifying an area as a communication destination;
Address acquisition means for acquiring address information of the communication device corresponding to the area specified by the area specifying means by referring to the correspondence information stored in the correspondence information storage means;
Transmission processing means for creating and transmitting a packet having the address information acquired by the address acquisition means as a transmission destination address;
A communication system comprising: In claim 2,
The transmission processing means creates a multicast distribution packet for the terminal device connected to the communication device specified by the transmission destination address. In any one of Claims 1-3,
The terminal device is mounted on a vehicle,
The communication device is an access point that is wirelessly connected to the terminal device mounted on a vehicle traveling in a predetermined communication area.

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