JP3997146B2 - Mobile communication system, network system, and mobile communication method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile communication system, a network system, and a mobile communication method for communicating information and the like with a mobile object such as a railway vehicle (train). In particular, the present invention relates to a mobile communication system, a network system, and a mobile communication method that can quickly reconfigure a network path established in a mobile body.
[0002]
[Prior art]
Conventionally, a computer network (hereinafter also simply referred to as a “network”) has been established in which a plurality of computers are connected by a communication line and the like, and data and programs are stored and exchanged between the plurality of computers and data is shared. ing.
[0003]
As such a network system, in accordance with the communication protocol TCP (Transmission Control Protocol) / IP (Internet Protocol), in principle, an open network system Internet in which computers can be freely connected, and the network as a host computer, etc. There is a closed network type intranet, etc., in which terminal devices such as computers that are managed and connected are restricted by certain security restrictions so that unmanaged computer nodes are not connected to the network.
[0004]
Among the communication services on the Internet, there is a mobile communication service using a mobile phone or the like. Currently, in railways, communication between crew members and on-board equipment in trains and ground commands and communication devices is carried out by voice communications and data communications using train radios, crew radios, or mobile phones. . Passengers use mobile phones, small information terminals, and the like from trains to make individual calls to access points such as Internet Service Providers (ISPs) and use services such as mail and Web.
[0005]
As a network system in a railway, there is JP-A No. 2002-111702 filed earlier by the present applicant.
[0006]
FIG. 27 is a diagram showing a network system disclosed in Japanese Patent Laid-Open No. 2002-111702. This network system is installed in a communication network 80, which is a computer network such as the Internet or an intranet, and each train of the A train 20a and the B train 20b, which are mobile bodies, and the A train onboard communication program and the B train onboard communication program. Installed in each of the mobile communication devices 22a and 22b that execute the on-board communication program such as the A train 20a and the B train 20b, which are mobile units, travel product sales, on-board equipment control and monitoring, and abnormal information Wireless communication between the trains 20a and 20b and the mobile business devices 21a and 21b that execute the on-board business programs such as the A-train on-board business program and the B-train on-board business program, which are collection and provision applications Train radio system 30, train radio system 30, and communication network Between the train wireless central station 50 that relays information to and from the station 0, the station wireless LAN 41 that performs wireless communication with the in-train LAN of each train 20a, 20b, and the station wireless LAN 41 and the communication network 80. A relay station network 40, a mobile phone from each train 20 a, 20 b and a base station 60 that relays communication using the PHS (Personal Handy Phone System) system, and a mobile phone network 90 that connects the base station 60 and the communication network 80. And a host 70 for storing and exchanging information and processing, and the A train ground business program 11a and the B train ground business program 11b corresponding to the on-board business program and the on-board communication program executed in each train 20a, 20b. A train ground communication program 12a, B train ground communication program 12b, etc. It includes a terrestrial communication server 10 to be processed, a.
[0007]
Here, a paired communication program exists on the ground communication server 10 and each A train 20a and B train 20b for each train (each A train 20a and each B train 20b). Communication is always performed via this communication program pair (hereinafter, the communication program on the ground and on the vehicle as a pair is also referred to as “terrestrial communication program” and “on-vehicle communication program”, respectively). Therefore, in the relationship between the A train 20a and the ground communication server 10, the "A train ground communication program 12a" and the "A train on-vehicle communication program (executed by the mobile communication device 22a)" form a pair, and the B train 20b In relation to the ground communication server 10, "B train ground communication program 12b" and "B train on-vehicle communication program (executed by the mobile communication device 22b)" form a pair.
[0008]
In addition, when the traveling trains 20a and 20b and the ground communication server 10 communicate with each other, it is used as a communication transmission method such as a mobile phone, train radio, crew radio, or when stopping at a station. Station wireless LAN 41, PHS, etc. can be considered.
[0009]
According to this network system, in communication with a mobile body (trains 20a, 20b), seamless communication can be performed without the user being aware of the communication transmission method and communication state.
[0010]
[Problems to be solved by the invention]
Here, in the case of a train as described above, in the course of train operation, a plurality of trains are connected to form one train, or a train is divided into a plurality of trains and operated as a plurality of trains. There is a case.
[0011]
As described above, when a change occurs in the composition during the operation, a radio device that can be used on the vehicle may be changed. That is, usually, one or more wireless devices are used for a mobile communication device on a vehicle. When a plurality of trains are merged, a mobile communication device on a plurality of vehicles uses a radio of any one of the mobile communication devices. Depending on the mobile communication device, there is a radio that can be used. It may change.
[0012]
In this case, it is necessary to change the route of the communication packet that flows between the ground (ground communication server) and the vehicle (mobile communication device). This route change is also necessary to prevent the loss of the communication packet. It is necessary to immediately perform when the operation state of the radio changes due to the division or merge of the knitting.
[0013]
As described above, in a train in which the access point changes at high speed, it is necessary to quickly change the route by dividing or merging vehicles.
[0014]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a mobile communication system, a network system, and a mobile communication system that can quickly reconfigure a communication path and prevent loss of communication packets in communication with a mobile object. It is to provide a body communication method.
[0015]
[Means for Solving the Problems]
In order to solve the above problems, a mobile communication system according to the present invention includes: Consists of traveling vehicles such as trains A mobile communication system provided in a mobile body, a communication device that communicates information with the outside, an on-board communication server that is connected to the communication device and controls communication with the outside, and an IP address in advance Preparing, dynamically assigning the IP address and automatically setting network parameters for information communication, a sub-network connecting the on-board communication server and the address control server, and other sub-networks A connection interface for connecting to a network, and a connection router provided between the subnetwork and the connection interface and detecting that the connection interface is connected to another subnetwork. If it is detected that it is connected to another subnetwork, it is connected to another subnetwork. An IP address is obtained from another address control server and routing between the sub-networks is performed, and the on-board communication server is connected to the other sub-network via the connection router in response to the stop of the communication device. A communication link with another on-board communication server is established.
[0016]
Here, the on-board communication server can communicate information with the outside by another communication device connected to another on-board communication server.
[0017]
The on-board communication server Execute an on-vehicle communication program that communicates with a communication program provided outside in order to perform seamless communication between the moving body and the outside The mobile communication device, the address control server may be a DHCP server, the connection interface may be a jumper line, and the communication device may be a wireless communication device.
[0018]
In addition, the on-board communication server can establish a communication link with another on-board communication server connected to another sub-network by multicast packet communication. At this time, the communication link may be a packet tunnel between the on-board communication server and another on-board communication server.
[0019]
Moreover, in order to solve the said subject, the network system of the 1st aspect of this invention is via a communication network, On the ground Such as trains A plurality of vehicles that are connected and run With moving objects Among A network system for communication, Among multiple mobile objects A first mobile communication system which is provided in the first mobile and performs communication of information; On the ground A first ground communication server connected to the communication network and transmitting / receiving information to / from the first mobile communication system; Connected to the first mobile body among the plurality of mobile bodies A second mobile communication system which is provided in the second mobile body and communicates information; On the ground A second ground communication server that is connected to the communication network and transmits / receives information to / from the second mobile communication system. The first and second mobile communication systems include the mobile communication described above. A connected router of the second mobile communication system is a system, Of the second mobile communication system When it is detected that the connection interface is connected to the sub-network of the first mobile communication system, the IP address is acquired from the address control server of the first mobile communication system to obtain the first and second mobile communication systems. The on-board communication server of the second mobile communication system Of the second mobile communication system Depending on the stoppage of the communication device Of the second mobile communication system Establishing a communication link with the on-board communication server of the first mobile communication system connected to the sub-network of the first mobile communication system via the connection router, and The on-board communication server is requested to establish a communication link with the second ground communication server, and the on-board communication server of the first mobile communication system is the on-board communication server of the second mobile communication system. The communication link is established with the second ground communication server via the communication device of the first mobile communication system in response to the communication link establishment request from the first mobile communication system.
[0020]
Here, the communication link may be a packet tunnel between the on-board communication server and the second ground communication server of the first mobile communication system.
[0021]
Moreover, in order to solve the said subject, the network system of the 2nd aspect of this invention is via a communication network, On the ground Such as trains A plurality of vehicles that are connected and run With moving objects Among A network system for communication, Out of multiple moving objects A first mobile communication system which is provided in the first mobile and performs communication of information; On the ground A first ground communication server connected to the communication network and transmitting / receiving information to / from the first mobile communication system; Connected to the first mobile body among the plurality of mobile bodies A second mobile communication system which is provided in the second mobile body and communicates information; On the ground A second ground communication server that is connected to the communication network and transmits / receives information to / from the second mobile communication system. The first and second mobile communication systems include the mobile communication described above. A connected router of the second mobile communication system is a system, Of the second mobile communication system When it is detected that the connection interface is separated from the sub-network of the first mobile communication system, the IP address acquired from the address control server of the first mobile communication system is discarded, and the second mobile The on-board communication server of the communication system establishes a communication link with the second ground communication server through the communication device of the second mobile communication system.
[0022]
Here, the communication link can be a packet tunnel between the on-board communication server and the second ground communication server of the second mobile communication system.
[0023]
Also, the communication network can be the Internet or an intranet.
[0026]
Since the communication link is dynamically established by packet routing and multicast packet communication, the communication path can be quickly reconfigured in communication with the mobile unit when the mobile unit is separated or merged. And loss of communication packets can be prevented.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a mobile communication system, a network system, and a mobile communication method of the present invention will be described below with reference to the drawings.
[0028]
1 and 2 are diagrams showing an embodiment of a network system to which a mobile communication system of the present invention is applied. The network system is a communication network 40 that is a computer network such as the Internet or an intranet, and an X-organized on-vehicle communication system that is installed in each train that is a mobile body and executes each on-vehicle communication program, on-vehicle business program, and the like. A station access point 50A, which is a train radio base station that relays information between the 10X and Y knitted vehicle communication system 10Y, and the X knitted vehicle communication system 10X and Y knitted vehicle communication system 10Y and the communication network 40 And the B station access point 50B, the X ground communication server 20X that communicates with the X-knitted vehicle communication system 10X, the Y ground communication server 20Y that communicates with the Y-knitted vehicle communication system 10Y, X ground host that performs storage exchange and processing of information with the communication system 10X And bets 30X, and a, and Y ground host 30Y for performing such store-and processing of information between the Y knitting onboard communication system 10Y.
[0029]
Here, the on-vehicle communication system 10X is connected to the X communication device A16XA and the X communication device B16XB such as a wireless communication device that performs wireless communication with the A station access point 50A, and to the X communication devices 16XA and 16XB. An on-vehicle communication server 11X, such as a mobile communication device that controls communication with the device, and an IP address are prepared in advance, the IP address is dynamically assigned, and network parameters for information communication are automatically set. X on-vehicle address control server 12X such as a DHCP (Dynamic Host Configuration Protocol) server, and X on-vehicle LAN (Local Area Network) which is a sub-network connecting the X on-vehicle communication server 11X and the X on-vehicle address control server 12X 15a and other subnetwork Provided between connection interfaces 17Xa and 17Xb such as jumper wires for connection to (vehicle LAN) and X vehicle LAN 15a and connection interface 17Xa, and connection interface 17Xa connects to another sub-network (vehicle LAN) An X-linked router 13X that detects the occurrence of the failure, and an X-vehicle host 14X that executes a business program or the like. Here, as an example of the mobile communication device, there is a proxy server.
[0030]
Similarly, the Y-car train communication system 10Y is connected to the Y communication device A16YA and the Y communication device B16YB such as a wireless communication device that performs wireless communication with the B station access point 50B, and the Y communication devices 16YA and 16YB. A network parameter for automatically communicating information with the Y on-board communication server 11Y such as a mobile communication device that controls communication with the outside is prepared by assigning an IP address in advance and dynamically assigning the IP address. The Y on-board address control server 12Y such as a DHCP server set to the Y on-board communication server 11Y and the Y on-board address control server 12Y, the Y on-board LAN 15b, and other sub-networks (on-board LAN) and connection interfaces 17Ya and 17Yb such as jumper wires, and Y-vehicle LAN 1 b and the connection interface 17Ya, the Y connection router 13Y that detects that the connection interface 17Ya is connected to another sub-network (X-vehicle LAN 15a in FIG. 2), and the Y-vehicle that executes business programs and the like. And a host 14Y.
[0031]
In FIG. 1, the vehicle of the X-knitted vehicle communication system 10X and the vehicle of the Y-knitted vehicle communication system 10Y are separated, and the respective systems 10X, 10Y operate independently. Also, the vehicle of the X-knitted vehicle communication system 10X and the vehicle of the Y-knitted vehicle communication system 10Y in FIG. 2 are merged, and the systems 10X and 10Y are operating in combination.
[0032]
Here, there exists a ground communication server (X ground communication server 20X and Y ground communication server 20Y) corresponding to each on-vehicle communication system (each X-knitted vehicle communication system 10X and Y-knitted vehicle communication system 10Y), Communication between the vehicle and the ground is always performed via this server pair. Therefore, the X-knitted vehicle communication system 10X and the X ground communication server 20X are paired, and the Y-knitted vehicle communication system 10Y and the Y ground communication server 20Y are paired.
[0033]
Hereinafter, establishment (reconfiguration) of the communication link when the on-vehicle communication systems 10X and 10Y are merged and separated will be described.
[0034]
FIG. 3 is a flowchart showing the reconstruction of the communication link when the on-car communication systems 10X and 10Y are merged. 4-8 is a figure which shows the state of a communication link. Hereinafter, a case will be described in which the on-car communication systems 10X and 10Y are merged from the state of FIG. 1 to the state of FIG. 1 to 8, by merging the X organization and the Y organization, the Y connection router 13Y detects that it is connected to the on-vehicle LAN 15a by the connection of the connection I / F 17Ya and the connection I / F 17Xb (step 301). ).
[0035]
In response to this detection, the Y-linked router 13Y acquires an IP address belonging to the X-vehicle LAN 15a from the X-vehicle address control server 12X, and starts packet routing (step 302). As a result, the Y-linked router 13Y and the X-linked router 13X exchange route control information related to the respective on-vehicle LAN 15a and the on-vehicle LAN 15b by a route control information exchange protocol such as a RIP (Routing Information Protocol) protocol.
[0036]
The Y communication device A16YA and the Y communication device B16YB operated as shown in FIG. 1 before the merge, but after the merge, the Y communication device A16YA and the Y communication device B16YB are in a use stop state (FIG. 2), and the Y onboard communication server 11Y detects this. (Step 303). In response to this detection, the Y onboard communication server 11Y notifies that the wireless link (communication link with the Y ground communication server 20Y) by the self-organized Y communication device A16YA and Y communication device B16YB is stopped. The “radio link notification (stop)” multicast packet and the “radio link request” multicast packet for requesting the communication link are transmitted (step 304).
[0037]
The two multicast packets are transmitted to the on-vehicle LAN 15a via the Y connection router 17Ya and received by the on-vehicle communication server 11X (step 305).
[0038]
The on-vehicle communication server 11X is operating a wireless link (communication link with the X ground communication server 20X) by the self-organized X communication device A16XA or X communication device B16XB according to the “wireless link request” multicast packet. A “radio link notification (operation)” multicast packet is transmitted to notify that it is. This “radio link notification (operation)” multicast packet arrives at the Y onboard communication server 11Y in the reverse flow to step 305 (step 306).
[0039]
In response to the “radio link notification (operation)” multicast packet, the Y onboard communication server 11Y configures (establishes) an onboard packet tunnel (communication link) with the X onboard communication server 11X (step 307). ). This specific method is disclosed in Japanese Patent Application Laid-Open No. 2002-111702 filed earlier by the present applicant, and this on-vehicle packet tunnel (communication link) is configured by automatic routing of an IP address by an IP table ( Established).
[0040]
FIG. 4 shows the establishment of a communication link from step 302 to step 307. After the configuration of the on-vehicle packet tunnel, the Y on-vehicle communication server 11Y is configured to transmit a packet other than the addressed node to the X on-vehicle communication server 11X via the on-vehicle packet tunnel. Set control information. The packet addressed to the on-vehicle communication server 11X is set to be transmitted to the Y-linked router 13Y. Furthermore, the X on-board communication server 11X sets the route control information so that the packet addressed to the Y on-board LAN 15b is transmitted to the Y on-board communication server 11Y via this on-vehicle packet tunnel.
[0041]
On the other hand, since the communication link (X-vehicle-X terrestrial packet tunnel) between the X-vehicle communication server 11X and the X-ground communication server 20X is already configured, the X-vehicle communication server 11X is connected to the communication network 40. Packet exchange (communication) is possible via the X ground communication server 20X with a server or host connected to the. Therefore, in the process up to step 307, transmission of the packet from the Y onboard communication server 11Y to the Y ground communication server 20Y is possible (FIG. 5). Therefore, the Y onboard communication server 11Y establishes a communication link (packet tunnel) between the X onboard communication server and the Y ground communication server 20Y.
Data requesting (configuration) is transmitted (step 308).
[0042]
Thereby, a communication link (X vehicle-Y ground packet tunnel) is established between the X vehicle communication server 11X and the Y ground communication server 20Y.
(Configuration) (Step 309: FIG. 6). The Y ground communication server 20Y sets the route control information so that the packet addressed to the Y vehicle host 14Y passes through this communication link (X vehicle-Y ground packet tunnel) (step 310).
[0043]
Thereby, packet exchange (communication) between the Y ground host 30Y and the Y onboard host 14Y becomes possible as shown in FIG. FIG. 8 shows packet exchange (communication) between the X-vehicle host 14X and the Y-vehicle host 14Y. As shown in FIG. 7, in the case of packet transmission from the Y onboard host 14Y, the transmitted packet is transmitted directly from the X ground communication server 20X to the Y ground host 30Y (dotted line arrow), but in the opposite case The packet from the Y ground host 30Y is transmitted to the X ground communication server 20X via the Y ground communication server 20Y (solid arrow).
[0044]
Next, a description will be given of a case where the knitted vehicle communication systems 10X and 10Y are divided (separated) from the knitting shown in FIG.
[0045]
FIG. 9 is a flowchart showing the configuration of the communication link when the on-car communication systems 10X and 10Y are divided (separated). FIG. 10 is a diagram showing a state of a communication link of the on-car communication system 10Y when the on-car communication systems 10X and 10Y are divided (separated).
[0046]
In FIG. 1, FIG. 2, FIG. 9 and FIG. 10, when the connection I / F 17Xb and the connection I / F 17Ya are disconnected due to the division of the formation (step 901), the Y connection router 13Y detects this and detects the on-vehicle LAN 15a. And the Y-vehicle LAN 15b stop routing packets (step 902).
[0047]
The Y communication device A16YA and the Y communication device B16YB are in a use suspended state before the division as shown in FIG. 2, but after the division, they are in a communicable state (step 903), and the Y communication device A16YA or the Y communication device. A wireless link is established between B16YB and the B station access point 50B (step 904).
[0048]
When the on-vehicle communication server 11Y detects the establishment of this wireless link, it transmits a “radio link notification (operation)” multicast packet (step 905). However, in the case of FIG. 1, since the communication state of the X organization does not change, an operation corresponding to transmission of this multicast packet does not occur.
[0049]
Establishment of a communication link (Y on-vehicle-Y ground packet tunnel: FIG. 10) between the Y on-board communication server 11Y and the Y ground communication server 20Y is performed by the same method as described above (step 906). This enables communication (packet exchange) between the Y-vehicle host 14Y and the Y ground host 30Y.
[0050]
11 and 12 are diagrams showing the merged / separated state of three knitting. First, the case where the state shown in FIG. 11 is changed to the state shown in FIG. 11 and 12, the newly added Z-knitted vehicle system has the same configuration as the X-knitted vehicle system shown in FIGS. 1 and 2.
[0051]
FIG. 13 is a flowchart showing the configuration of the communication link when the state of FIG. 11 is changed to the state of FIG. Moreover, FIGS. 14-19 is a figure which shows the state of a communication link.
[0052]
In FIGS. 11 to 19, the Z connection router 13 </ b> Z detects that it is connected to the LAN 15 a on the X vehicle by connecting the connection I / F 17 Za and the connection I / F 17 Xb by merging the formations from FIG. 11 to FIG. 12. (Step 1301).
[0053]
In response to this detection, the Z-linked router 13Z acquires an IP address belonging to the X-vehicle LAN 15a from the X-vehicle address control server 12X, and starts packet routing (step 1302: FIG. 14). As a result, the Z-linked router 13Z and the X-linked router 13X exchange route control information related to the respective on-vehicle LAN 15a and the on-vehicle LAN 15c by using a routing information exchange protocol such as a RIP (Routing Information Protocol) protocol (Step S1). 1303: FIG. 14).
[0054]
The Z communication device A16ZA operated as shown in FIG. 11 before the merge, but after the merge, the Z communication device A16ZA enters a use stop state (FIG. 12), and the Z on-board communication server 11Z detects this (step 1304). "Radio link notification (stop)" multicast packet for notifying that the radio link (communication link with Z ground communication server 20Z) by the self-organized Z communication device A16ZA and Z communication device B16ZB is stopped Then, a “wireless link request” multicast packet for requesting a communication link is transmitted (step 1305: FIG. 14).
[0055]
These two multicast packets are transmitted to the on-vehicle LAN 15a via the Z connection router 13Z, received by the on-vehicle communication server 11X, and transmitted to the Y onboard LAN 15b via the Y connection router 13Y. It is received by the on-vehicle communication server 11Y (step 1306: FIG. 14).
[0056]
The on-vehicle communication server 11X is operating a wireless link (communication link with the X ground communication server 20X) by the self-organized X communication device A16XA or X communication device B16XB according to the “wireless link request” multicast packet. A “radio link notification (operation)” multicast packet for notifying that this is transmitted (step 1307: FIG. 14).
[0057]
This “radio link notification (operation)” multicast packet arrives at the Z on-board communication server 11Z in the reverse flow to step 1306 (step 1308: FIG. 14), and at the same time, the Y vehicle passes through the Y connection router 13Y. The upper communication server 11Y is reached (step 1309: FIG. 14). On the other hand, the Y on-board communication server 11Y transmits a “radio link notification (stop)” multicast packet notifying that the self-organized communication link is stopped (step 1310: FIG. 14).
[0058]
The Y on-board communication server 11Y is configured such that the communication link between the Z on-board communication server 11Z and the Z ground communication server 20Z becomes unusable, and between the X on-board communication server 11X and the X ground communication server 20X. , The network is reconfigured so as to establish a communication link from the on-vehicle communication server 11X (step 1311). The specific method is the same as the above-described step 307 to step 310 (FIGS. 14 to 19).
[0059]
FIG. 20 is a flowchart showing the configuration of the communication link when the composition is divided (separated) from FIG. 12 to FIG. FIGS. 21 to 26 are diagrams showing the state of the communication link when the composition is divided (separated).
[0060]
In FIG. 11, FIG. 12, FIG. 20 to FIG. 26, when the connection I / F 17Xb and the connection I / F 17Za are disconnected due to the division of the knitting (step 2001), the Z connection router 13Z detects this and detects the on-vehicle LAN 15a. And the routing of the packet between the Z onboard LAN 15c are stopped (step 2002). At this time, the route control tables are exchanged between the Z-linked router 13Z and the Y-linked router 13Y by a route information exchange protocol such as the RIP protocol (step 2003). As a result, although the Y organization remains capable of exchanging packets with the Z organization, it cannot exchange packets with the X organization.
[0061]
The Z communication device A16ZA and the Z communication device B16ZB were in a use stop state before the division as shown in FIG. 12, but after the division, they became communicable, and the Z communication device A16ZA or the Z communication device B16ZB and the B station A wireless link with the access point 50B is established.
[0062]
When the Z on-board communication server 11Z detects the establishment of this wireless link (step 2004), it transmits a “radio link notification (operation)” multicast packet (step 2005).
[0063]
The multicast packet is transmitted to the Y onboard LAN 15b via the Y connection router 13Y and received by the Y onboard communication server 11Y (step 2006). The on-vehicle communication server 11Y establishes a communication link in the same manner as the above-described steps 307 to 310 (step 2007: FIGS. 3 and 22 to 26). This enables communication (packet exchange) between the Y-vehicle host 14Y and the Y ground host 30Y.
[0064]
The mobile communication system, the network system, and the mobile communication method of the present invention have been described above. For example, in FIG. 11, when the Y-knitting system is merged with the XZ knitting system, FIGS. The operation of the X organization system and the Y organization system shown in FIG. 8 constitutes a communication link similar to the organization shown in FIG.
[0065]
When the Y knitting is separated from the knitting of FIG. 12, the X-Z knitted communication link and the Y knitted communication link are operated by the operations of the X knitting system and the Y knitting system shown in FIGS. Is rebuilt.
[0066]
【The invention's effect】
As described above, according to the mobile communication system, the network system, and the mobile communication method of the present invention, the communication link is dynamically established by packet routing and multicast packet communication. When merging, the communication path can be quickly reconfigured in communication with a mobile unit, and the loss of communication packets can be prevented.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a network system of the present invention.
FIG. 2 is a diagram illustrating an example of a network system according to the present invention.
FIG. 3 is a flowchart showing processing for reconstructing a communication link.
FIG. 4 is a diagram showing a state of a communication link.
FIG. 5 is a diagram showing a state of a communication link.
FIG. 6 is a diagram showing a state of a communication link.
FIG. 7 is a diagram showing a state of a communication link.
FIG. 8 is a diagram showing a state of a communication link.
FIG. 9 is a flowchart showing processing for reconstructing a communication link.
FIG. 10 is a diagram showing a state of a communication link.
FIG. 11 is a diagram illustrating an example of a network system according to the present invention.
FIG. 12 is a diagram showing an example of a network system according to the present invention.
FIG. 13 is a flowchart showing processing for reconstructing a communication link.
FIG. 14 is a diagram showing a state of a communication link.
FIG. 15 is a diagram showing a state of a communication link.
FIG. 16 is a diagram showing a state of a communication link.
FIG. 17 is a diagram showing a state of a communication link.
FIG. 18 is a diagram showing a state of a communication link.
FIG. 19 is a diagram showing a state of a communication link.
FIG. 20 is a flowchart showing processing for reconstructing a communication link.
FIG. 21 is a diagram showing a state of a communication link.
FIG. 22 is a diagram showing a state of a communication link.
FIG. 23 is a diagram showing a state of a communication link.
FIG. 24 is a diagram showing a state of a communication link.
FIG. 25 is a diagram illustrating a state of a communication link.
FIG. 26 is a diagram showing a state of a communication link.
FIG. 27 shows an example of a conventional mobile communication system.
[Explanation of symbols]
10X X knitting car system
10Y Y-car train system
10Z Z system on-vehicle system
11X X on-board communication server
11Y Y on-board communication server
11Z Z on-board communication server
12X X on-board address control server
12Y Y On-board address control server
12Z Z on-board address control server
13X X connected router
13Y Y-linked router
13Z Z-linked router
14X X On-vehicle host
14Y Y car host
14Z Z on-board host
15a X On-vehicle LAN
15b Y on-vehicle LAN
15c Z onboard LAN
16XA X communication device A
16XB X communication device B
16YA Y communication device A
16YB Y communication device B
16ZA Z communication device A
16ZB Z communication device B
17Xa, 17Xb, 17Ya, 17Yb, 17Za, 17Zb Connection I / F
20X X ground communication server
20Y Y ground communication server
20Z Z ground communication server
30X X ground host
30Y Y ground host
30Z Z ground host
40 Communication network
50A A station access point
50B station access point

Claims (13)

A mobile communication system provided in a mobile body constituted by a traveling vehicle such as a train,
A communication device for communicating information with the outside;
An on-board communication server connected to the communication device and controlling communication with the outside;
An address control server that prepares an IP address in advance, dynamically assigns the IP address, and automatically sets network parameters for information communication;
A sub-network connecting the on-board communication server and the address control server;
A connection interface for connecting to other sub-networks;
A connected router provided between the sub-network and the connection interface and detecting that the connection interface is connected to the other sub-network,
When the connection router detects that the connection interface is connected to the other subnetwork, the connection router obtains an IP address from another address control server connected to the other subnetwork, and performs routing between the subnetworks. And
The on-board communication server establishes a communication link with another on-board communication server connected to the other sub-network via the connection router in response to the stop of the communication device. A mobile communication system.   2. The mobile communication system according to claim 1, wherein the on-board communication server communicates information with the outside by using another communication device connected to the other on-board communication server. . The on-vehicle communication server executes an on-vehicle communication program for performing communication with the communication program provided outside in order to perform seamless communication between the mobile and the outside. The mobile communication system according to claim 1, wherein:   4. The mobile communication system according to claim 1, wherein the address control server is a DHCP (Dynamic Host Configuration Protocol) server. 5.   The mobile communication system according to any one of claims 1 to 4, wherein the connection interface is a jumper line.   The mobile communication system according to claim 1, wherein the communication device is a wireless communication device.   The said on-board communication server establishes a communication link with the other on-board communication server connected to the said other subnetwork by communication of a multicast packet, The any one of Claim 1 to 6 characterized by the above-mentioned. Mobile communication system.   8. The mobile communication system according to claim 7, wherein the communication link is a packet tunnel between the on-board communication server and the other on-board communication server. A network system for performing communication between a plurality of mobile objects composed of vehicles traveling on the ground and connected via a communication network,
A first mobile communication system which is provided in a first mobile body among the plurality of mobile bodies and performs communication of information;
A first ground communication server provided on the ground, connected to the communication network, and transmitting and receiving information to and from the first mobile communication system;
A second mobile communication system that is provided in a second mobile body connected to the first mobile body among the plurality of mobile bodies and performs communication of information;
A second ground communication server that is provided on the ground and connected to the communication network, and transmits and receives information to and from the second mobile communication system,
The first and second mobile communication systems are mobile communication systems according to any one of claims 1 to 7,
When the connecting router of the second mobile communication system detects that the connection interface of the second mobile communication system is connected to the sub-network of the first mobile communication system, the first mobile Obtaining an IP address from the address control server of the mobile communication system and performing routing between the sub-networks of the first and second mobile communication systems;
The on-board communication server of the second mobile communication system receives the first communication via the connection router of the second mobile communication system in response to the stop of the communication device of the second mobile communication system . Establishing a communication link with the on-board communication server of the first mobile communication system connected to the sub-network of the first mobile communication system, and for the on-board communication server of the first mobile communication system Request to establish a communication link with the second terrestrial communication server,
The on-board communication server of the first mobile communication system changes the communication device of the first mobile communication system in response to a communication link establishment request from the on-board communication server of the second mobile communication system. And establishing a communication link with the second terrestrial communication server.   The network system according to claim 9, wherein the communication link is a packet tunnel between an on-board communication server of the first mobile communication system and the second ground communication server. A network system for performing communication between a plurality of mobile objects composed of vehicles traveling on the ground and connected via a communication network,
A first mobile communication system which is provided in a first mobile body among the plurality of mobile bodies and performs communication of information;
A first ground communication server provided on the ground, connected to the communication network, and transmitting and receiving information to and from the first mobile communication system;
A second mobile communication system that is provided in a second mobile body connected to the first mobile body among the plurality of mobile bodies and performs communication of information;
A second ground communication server that is provided on the ground and connected to the communication network, and transmits and receives information to and from the second mobile communication system,
The first and second mobile communication systems are mobile communication systems according to any one of claims 1 to 7,
When the connecting router of the second mobile communication system detects that the connection interface of the second mobile communication system is separated from the sub-network of the first mobile communication system, the first mobile discards the IP address that was acquired from the address control server body communication system, the on-train communication server of the second mobile communication system via the communication device of the second mobile communication system, wherein A network system, characterized in that a communication link is established with a second ground communication server.   The network system according to claim 11, wherein the communication link is a packet tunnel between an on-board communication server of the second mobile communication system and the second ground communication server.   The network system according to claim 9, wherein the communication network is the Internet or an intranet.

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