JP4508051B2 - Mobile device and program - Google Patents

Description

  The present invention relates to a mobile device that uses a mobile IP protocol and performs communication while moving.

  With the development of wireless communication technology and the spread of the Internet, the importance of mobile IP technology that continues communication while switching connection points or connection networks while moving is increasing.

  Mobile IP is a technique for maintaining a session by concealing the movement of a moving communication terminal. Specifically, when the home agent device is installed in the home network of the communication terminal and the communication terminal is connected from an external network that is a network other than the home network, the home agent device obtains the care-of address acquired from the external network. Register with. The home agent device stores the care-of address of the communication terminal in association with the home address of the communication terminal, captures a packet destined for the home address, encapsulates and transfers the packet with the associated care-of address. Accordingly, other communication terminals on the network can communicate with the moving communication terminal using only the home address regardless of the moving location of the moving communication terminal. (For example, refer nonpatent literature 1 and 2.).

  Further, in the mobile IP, a configuration that enables a communication terminal having a plurality of communication media to simultaneously use different communication media by associating and storing a plurality of care-of addresses with respect to one home address. (For example, refer nonpatent literature 3).

  Hereinafter, a device that registers a care-of address given from an external network in the home agent device according to the mobile IP protocol and conceals its movement from other communication terminals is called a mobile device.

C. Perkins, “IP Mobility Support for IPv4”, IETF RFC 3344, August 2002 D. Johnson, C.I. Perkins, J.M. Arkko, “Mobility Support in IPv6”, IETF RFC 3775, June 2004 R. Wakikawa, K .; Uehara, T .; Ernst, K.M. Nagami, “Multiple Care-of Addresses Registration”, IETF INTERNET DRAFT draft-wakawakawa-mobileiple-multiplecoa-04. txt, June 2005

  Even in the current network environment, the network operator's policy or the purpose of the service is connected to the network that is not connected to the global network such as the Internet, or to the Internet. There is a network in which the connection between the mobile device and the home agent device cannot be secured because the access of the mobile agent and the home agent device is restricted (hereinafter, the network that cannot be connected to the home agent device when viewed from the mobile device is called a local net, A network that can be connected to a device is called a global network.)

  The current mobile device is premised on the presence of a home agent device, and has a problem that it cannot enjoy a service provided by a local network, which is a network that cannot secure a connection with the home agent device.

  In addition, when moving to the local net service area, the connection destination is switched from the global net to the local net by some method to enjoy the service provided by the local net, and conversely, when moving outside the local net service area In addition, even if the connection destination can be switched to the global network and the service provided on the global network can be enjoyed again, the service that was received from the network that was connected up to that point will continue along with the switchover. The problem that it cannot be received occurs.

  Therefore, an object of the present invention is to provide a mobile device capable of seamlessly switching between communication connected to a global net and communication connected to a local net.

According to the mobile device according to the invention,
A first communication medium that can be connected to both the global net that can communicate with the home agent device and a local net that cannot communicate with the home agent device, a second communication medium that can be connected only to the global net, and each communication medium Management registration means for managing the connection state with the network, and for registering the care-of address of the communication medium connected to the global network with the home agent device, and based on the connection state between the network managed by the management registration means , A control unit that distributes a packet to be transmitted to the global net and a packet to be transmitted to the local net to each communication medium, and the management registration unit includes The connection destination of communication media is changed from the global network to the local network. When it was changed to TMG, characterized in that to connect the second communication medium to the global Internet.

According to another embodiment of the mobile device of the present invention,
The management registration means receives a signal indicating that it is a local net on the first communication medium, or in response to a registration request signal transmitted to the home agent device via the first communication medium within a predetermined period. When the registration confirmation signal is not received from the home agent device, it is preferable that the connection destination of the first communication medium is determined as the local network, and otherwise it is determined as the global network.

According to another embodiment of the mobile device of the present invention,
The management registration unit is configured such that when the control unit is communicating with the global network using the first communication medium and the second communication medium is not connected to the global network, the connection destination of the first communication medium is local. It is also preferable to connect the second communication medium to the global network when the network is changed.

According to another embodiment of the mobile device of the present invention,
Managing registration means, when the third communication media connection of the first communication medium when not connected to a local net, was changed from the local net grayed b Barunetto, the third communication media It is also preferable to connect to the local net.

According to the program according to the present invention,
A computer having a first communication medium that can be connected to both a global net that can communicate with the home agent device and a local net that cannot communicate with the home agent device, and a second communication medium that can be connected only to the global net Is made to function as the mobile device.

  When the connection destination of the communication media is switched from the global net to the local net, if there is no other communication media connected to the global net, the management registration unit will select a communication media that can only be connected to the global net. By connecting to the global network, you can continue communication services that you have enjoyed from the global network. The management registration unit determines the connection destination of the communication medium by using the care-of address registration process, so that it is not necessary to newly install a special device on the local net or the global net.

  In addition, by installing a communication medium that can be connected only to the local net, the communication service that has been enjoyed from the local net can be continued even when the local net is switched to the global net.

  The best mode for carrying out the present invention will be described in detail below with reference to the drawings.

  FIG. 1 is a block diagram of a mobile device 1 according to the present invention. As shown in FIG. 1, the mobile device 1 includes communication media 11, 12, and 13, a control unit 14, and a management registration unit 15.

  The communication medium 11 is a communication medium that can be connected only to a global network, such as a communication medium that is wirelessly connected to a mobile communication network. The communication medium 12 is a global network such as a wireless LAN (Local Area Network), for example. The communication medium 13 is a communication medium that can be connected to both local networks, and the communication medium 13 is a communication medium that can be connected only to the local network, such as DSRC (Dedicated Short Range Communication) used in an intelligent transportation system.

  The control unit 14 performs processing according to the mobile IP protocol used for the transmission packet to the global net, outputs the transmission packet to the communication medium connected to the global net, and transmits the packet to the local net. As for the packet, the transmission packet is output to the communication medium connected to the local network. The management registration unit 15 manages whether the communication medium and its connection destination, that is, connected to the global net, connected to the local net, or not connected to the network. Based on the connection state of the communication media managed by the management registration unit 15, the transmission packet is allocated to the communication media.

  The management registration unit 15 monitors and manages the connection state of each communication medium to the network. FIG. 2 is a diagram illustrating an example of a connection state of each communication medium managed by the management registration unit 15. As shown in FIG. 2B, the value “0” of the connection destination identifier is not connected to the network, the value “1” is connected to the global net, and the value “2” is connected to the local net. It expresses that it is. FIG. 2A shows a state in which the communication medium 11 is connected to the global network, and the communication media 12 and 13 are not connected to the network. Note that the connection destination identifier value that the communication medium 11 can take is “0” or “1”, and the connection destination identifier value that the communication medium 12 can take is “0”, “1”, or “2”. The value of the connection destination identifier that the communication medium 13 can take is “0” or “2”.

  The management registration unit 15 sets the value of the connection destination identifier to “1” when the connection link with the network is established, and sets the value of the connection destination identifier to “0” when the connection link is disconnected. Similarly, for the communication medium 13, when the connection link with the network is established, the value of the connection destination identifier is “2”, and when the connection link is disconnected, the value of the connection destination identifier is “0”.

  In addition, when the communication medium 11 newly establishes or changes a connection link with the network, the management registration unit 15 performs registration processing of the care-of address acquired from the new connection destination in the home agent device. . Specifically, a registration request signal (BU signal: Binding Update) destined for the home agent device is transmitted from the communication medium 11 via the control unit 14, and the home agent device confirms reception of the received registration request signal. The registration confirmation signal (BA signal: Binding Acknowledgment) for transmitting the care-of address of the communication medium 11 to the destination is received via the control unit 14.

  On the other hand, for the communication medium 12, since it is not possible to determine whether the connection destination is a global net or a local net only by establishing a connection link with the network, the registration processing to the home agent device by the management registration unit 15 is used. To do. That is, when the connection link is established from the unconnected state and when the connection destination is changed, the management registration unit 15 sends a registration request signal addressed to the home agent device from the communication medium 12 via the control unit 14. When the registration confirmation signal is received within a predetermined period of time, if it is connected to the global net, if it is not received, it is determined that it is connected to the local net, and the connection destination identifier of the communication medium 12 is determined. Update.

  Further, the management registration unit 15 changes the communication medium 13 to the local net when the communication medium 12 is connected to the local net and the communication destination is changed from the state of communicating with the local net to the global net. The control unit 14 switches the communication with the local network via the communication medium 12 to the communication via the communication medium 13. Similarly, when the communication medium 12 is connected to the global net and communicates with the global net, the management registration unit 15 changes the communication medium 11 to the global network when the connection destination is changed to the local net. Then, the control unit 14 switches the communication with the global network that has been via the communication medium 12 to the communication via the communication medium 11. As a result, even if the switching between the global net and the local net occurs, the service received from the network before the switching can be continuously received. In addition, the communication media 11 and 13 do not need to be constantly activated, and power consumption can be suppressed.

  FIG. 3 is a process flow diagram in the management registration unit 15 when the communication medium 12 newly establishes a connection link to the network and when the connection destination of the connection link is changed. Note that the identifier of the connection destination is as shown in FIG.

  A BU signal is transmitted via the communication medium 12 (S1), and it is monitored whether or not the BA signal is received within a predetermined period (S2). When it is received within a predetermined period and the current identifier is 2 (S3), it is a connection change from the local net to the global net, and the management registration unit 15 communicates with the local net to the control unit 14 An inquiry is made as to whether it is in the middle (S4). If the communication with the local net is in progress, the communication medium 13 is connected to the local net in order to continue the communication with the local net, and the connection is notified to the control unit 14 after the connection (S5). The control unit 14 performs processing for switching the communication with the local network, which has been performed via the communication medium 12, to the communication medium 13. If the communication medium 13 is already connected to the local network, only the notification to the control unit 14 is made. Finally, the identifier of the connection destination of the communication medium 12 is changed to “1”.

  Similarly, if the BA is not received within a predetermined period in S2 and the current identifier is 1 (S7), the connection is changed from the global net to the local net, and the management registration unit 15 performs control. The unit 14 is inquired whether it is communicating with the global network (S8). If the communication with the global net is in progress, the communication medium 11 is connected to the global net in order to continue the communication with the global net, and the connection is notified to the control unit 14 after the connection (S9). The control unit 14 performs processing for switching the communication with the global network that has been performed via the communication medium 12 to be performed via the communication medium 11. When the communication medium 11 is already connected to the global network, only the notification to the control unit 14 is made. Finally, the identifier of the connection destination of the communication medium 12 is changed to “2”.

  Although not described in the flowchart of FIG. 3 for the sake of simplicity, the management registration unit 15 performs the home agent device via the communication medium 11 after completing the connection of the communication medium 11 to the network in S9 of FIG. Registration processing of the care-of address to the mobile device 1, that is, the transmission of the BU signal, so that the home agent device also changes the destination address of the packet addressed to the mobile device 1 from the care-of address of the communication media 12 so far to the communication media 11. It becomes possible to change to a care-of address.

  When the connection destination of the communication medium 12 is changed, the processing from S1 is started (S11). When the connection with the network is cut off (S12), the identifier of the connection destination is set to “0”. (S13).

  In the process of establishing a communication link when the local net is explicitly notified to the mobile device, a notification that the local net is a local net can be used in the process of S2. .

  As described above, first, at least one communication medium 12 that can be connected to both the global net and the local net is mounted, and the connection destination is global depending on whether or not the BA signal can be received with respect to the BU signal when connecting to the network or changing the connection destination. Switching between a global net and a local net is realized by determining and managing whether the network is a net or a local net. Further, by mounting at least one communication medium 11 that can be connected only to the global network, for example, for the mobile communication network, for example, the network that the communication medium 12 has changed based on the received power is a local network. Even in this case, it is possible to continue to receive services that were received via the global network before switching.

  Furthermore, by mounting at least one communication medium 13 that can be connected only to the local network, for example, even if the network that the communication medium 12 has changed based on the received power is a global network, the local network is switched before switching. It becomes possible to continue to receive the service that was received via.

  Even when a plurality of communication media 12 that can be connected to both the global net and the local net are mounted and each of them communicates with the global net and one of the communication media 12 is switched to the local net, The other communication media 12 can switch the communication via the switched communication media 12 to the other communication media 12 by deleting the registration of the switched communication media 12 in the home agent device.

FIG. 2 is a block diagram of a mobile device according to the present invention. It is a figure which shows the example of the connection condition of each communication medium which a management registration part manages. It is a processing flow figure in a management registration part.

Explanation of symbols

1 Mobile device 11, 12, 13 Communication media 14 Control unit 15 Management registration unit

Claims (5)

A first communication medium connectable to both a global net that can communicate with the home agent device and a local net that cannot communicate with the home agent device;
A second communication medium that can only be connected to the global network;
Management registration means for managing the connection state of each communication medium with the network, and registering the care-of address of the communication medium connected to the global network with the home agent device,
A control unit that distributes a packet to be transmitted to the global net and a packet to be transmitted to the local net to each communication medium based on a connection state with the network managed by the management registration unit;
When the second communication medium is not connected to the global net and the connection destination of the first communication medium is changed from the global net to the local net, the management registration means selects the second communication medium. A mobile device characterized by being connected to the global net.   The management registration means receives a signal indicating that it is a local net on the first communication medium, or in response to a registration request signal transmitted to the home agent device via the first communication medium within a predetermined period. 2. The connection destination of the first communication medium is determined as a local network when a registration confirmation signal is not received from the home agent device, and is determined as a global network in other cases. Mobile devices.   The management registration unit is configured such that when the control unit is communicating with the global network using the first communication medium and the second communication medium is not connected to the global network, the connection destination of the first communication medium is local. The mobile device according to claim 1 or 2, wherein the second communication medium is connected to the global network when the network is changed. Having a third communication medium that can only be connected to the local net,
Managing registration means, when the third communication media connection of the first communication medium when not connected to a local net, was changed from the local net grayed b Barunetto, the third communication media The mobile device according to claim 1, wherein the mobile device is connected to a local net. A first communication medium connectable to both a global net that can communicate with the home agent device and a local net that cannot communicate with the home agent device;
A computer having a second communication medium connectable only to the global net;
Management registration means for managing the connection state of each communication medium with the network, and registering the care-of address of the communication medium connected to the global network with the home agent device,
A control unit that distributes a packet transmitted to the global net and a packet transmitted to the local net to each communication medium based on a connection state with the network managed by the management registration unit;
A program that allows
When the second communication medium is not connected to the global network and the connection destination of the first communication medium is changed from the global network to the local network, the management registration means A program that functions to connect to the global net.

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