JPH0695998A - Mobile communication device - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a mobile communication device that reduces the overhead of address translation when moving on the network with address change. [Structure] Referring to the multiple address holding unit 2 that holds all addresses in the previous destination network, the multiple address control unit 3 determines whether or not address translation is necessary. When communicating with an address on the current network, communication is performed without address conversion. If not,
The mobile communication control unit 1 performs address conversion. This allows continuous communication to the application regardless of movement. As a result, for applications started at the destination, the overhead for mobile communication is reduced compared to the conventional method, and if the operation at the destination takes a certain amount of time, the Applications that have been running continuously will end gradually, and eventually all applications will be started on the move destination, and a smooth environment transition can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication device that moves a connection point on a network and is assigned a different address for each connection point. With regard to improvements for continuous communication with.

[0002]

2. Description of the Related Art In recent years, portable computers, which are made smaller and lighter by the progress of electronic technology, are becoming popular.
In this type of computer, it is conceivable that a computer connected to the network is temporarily separated from the network and moved, and then connected to the network and used again at the destination.

By the way, each node (computer) connected to the network is assigned an address for identifying it. However, if the address changes depending on the destination such as the location information of the connection point is included in this address, and if a node on the network moves, it becomes necessary to reconfigure a new address. It becomes impossible to communicate continuously.

Therefore, it has been proposed to allocate two addresses to a moving node as a communication method for performing continuous communication before and after the movement of a computer. That is, the VIP approach of Sony Computer Science Laboratories (reference: "VIP: Virtual Internet Protocol", Fumio Teraoka, Yasuhiko Yokote,
Mariko Tokoro, IPSJ Technical Committee Report-Multimedia Communication and Distributed Processing-1991.7.5) defines a virtual address called a home address, and a mobile node actually uses the home address and the destination network. Has a real address used for communication.

Below, in the above VIP approach,
A state in which the mobile node holds a home address and a real address, and a flow of processing for performing continuous communication before and after moving will be described. FIG. 3 is a diagram showing the configuration of a mobile node in the VIP approach. In the figure,
A higher-level communication control unit 14 receives a transmission request from an application or process and a received packet from the mobile communication control unit 11 and performs transmission / reception processing.

Reference numeral 15 is a lower-order communication control unit which actually performs communication via the network. 16 is a communication line.
Reference numeral 11 is a mobile communication control unit that realizes mobile communication, refers to the home address holding unit 12, converts the home address of the packet transmitted from the upper communication control unit 14 into a real address, and then converts the home address from the lower communication control unit 15. The real address of the received packet of is converted into the home address.

The home address holding unit 12 holds the home address of the mobile node. The operation of the mobile node in the VIP approach configured as described above will be described below. First, when a mobile node is connected to a new network by moving, the mobile node acquires an address used in the new network as follows. If the power of the node is not turned off when moving,
Only the lower communication control unit 15 is initialized to obtain the address in the new network. On the other hand, when the power is turned off, the lower communication control unit 15 is initialized along with the initialization when the power is turned on. Acquire an address in the new network. As a specific method of obtaining the address, BOOTP (reference: Bill Croft a)
nd John Gilmore, BOOTSTRAP
PROTOCOL, RFC951, Sep. , 198
There are methods such as the method of using 5) and the method of assigning and entering by the system administrator. The addresses obtained by these methods are held as real addresses by the mobile communication control unit 11 and used when the lower communication control unit 15 actually communicates via the network.

Next, when the mobile node transmits, a transmission request (including a source address, transmission data, an instruction regarding transmission) is sent from the upper communication control unit 14 to the mobile communication control unit 11.
Is passed. At this time, from the upper communication control unit 14,
A home address is designated as the source address. The mobile communication control unit 11 refers to the home address holding unit 12, converts the home address as the source address of the packet into a real address, and sends the packet in which the real address is set via the lower communication control unit 15. .

When the mobile node receives the packet, the packet addressed to the real address of the mobile node is received via the communication line 6 and passed to the mobile communication control unit 11. The mobile communication control unit 11 checks whether the real address designated by the received packet is addressed to the own node, and if the packet is addressed to the own node, converts it into a home address by referring to the home address holding unit 12 To the communication control unit 14.

As described above, the mobile node in the conventional system has a real address used for actual communication and a virtual home address that does not change even when it moves. as a result,
Even if the real address is changed due to the movement, the higher-level communication control unit 14 or the application only needs to use the same home address before and after the movement, so that the processing can be continuously executed without interruption. .

[0011]

However, according to the above conventional technique, the application in the mobile node can always communicate with one home address, but on the other hand, the overhead for associating the home address and the real address with each other. That is, there is a problem that a dead time is always generated due to the conversion processing between the home address and the real address.

In view of the above problems, it is an object of the present invention to provide a mobile communication device capable of continuous communication without interruption of processing before and after movement while reducing overhead.

[0013]

In order to solve the above-mentioned problems, the present invention is a mobile device which is connected to any one of connection points on a network, is assigned an address corresponding to the connection point, and communicates via the network. In the communication device, at the time of transmission, the transmission source address designated by the application and the address assigned to the device at that time are determined by the determination means and by the determination means. Address translation means for translating a source address designated by the application into an address assigned to the device when determined,
Is equipped with.

Further, the mobile communication device is connected to any one of the connection points on the network, is assigned an address corresponding to the connection point, and communicates via the network, when receiving a packet addressed to the mobile communication device. , A determination means for determining whether or not the packet is addressed to the application using the address assigned to the device at that time, and an address assigned to the device at that time is used by the determination means. Address translation means for translating the source address indicated by the packet into an address used by the application when it is determined that the application is not addressed to the application.

Further, there is provided holding means for holding an address which can be used by the application among the addresses previously assigned to the device in association with the application, and the address converting means refers to the holding means to store the address. It may be configured to convert.

Further, the above-mentioned application may continue to use the address assigned to the device at its startup even after the connection point is changed.

[0017]

With the above-mentioned means, in the mobile communication device of the present invention, at the time of transmission, the judging means judges whether the address at the current connection point and the address designated by the application match. In response to this determination result, the address conversion means refers to the plural address holding means only when the addresses do not match, converts the address into the address of the current connection point, and stores the correspondence relationship of the address conversion in the holding means. , If they match, the address is not translated.

Further, at the time of reception, the determination means determines whether or not the received packet is addressed to the application using the address assigned to the device at that time. In response to this determination result, when the address assigned to the device at that time is not addressed to the application, the address translation unit refers to the holding unit to translate the address into the address used by the application, Further, if the address is assigned to the application using the address assigned to the device at that time, the address is not translated.

In this way, if the address used by the application is the address at the current connection point, there is no need to translate the address, and the overhead is significantly reduced.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A multi-address mobile communication device according to an embodiment of the present invention will be described below with reference to the block diagram shown in FIG. A mobile communication control unit 1 has a destination address translation unit 7 and a source address translation unit 8 which will be described later, and performs address translation.

Reference numeral 2 denotes a plural address holding unit, which holds the addresses acquired from the network in order every time it moves. Three
Is a multiple address control unit, and determines whether the address used in the transmission request (transmission data) received from the higher-level communication control unit 4 matches the real address currently used by the mobile node, If they match, the transmission request (transmission data) is directly output to the lower communication control unit 5,
If they do not match, the mobile communication control unit 1 is activated to convert the address and then output.

Reference numeral 4 denotes a higher-level communication control unit, which is a transmission request from an application or process and a mobile communication control unit 11
It receives and receives the received packet from and performs transmission / reception processing. 5
Is a subordinate communication control unit that controls the actual communication via the network. A communication line 6 is connected to the network. The destination address conversion unit 7 converts the destination address into an address used by the application when receiving.

The source address translation unit 8 translates the source address used by the application at the time of transmission into the address currently assigned to the mobile node. The operation of the multi-address communication device according to the embodiment of the present invention configured as described above will be described below. The multi-address communication device (mobile node) on the network allows the application on the mobile node to continue communication when the address used for actual communication changes due to physical movement on the network. The following is a description of a state in which all addresses in the networks connected so far are held in the mobile node, and communication is performed while associating the addresses with each other.

First, how the mobile node holds a plurality of addresses as it moves will be described. The method by which the mobile node moves and boots in the new network can be divided into the following two cases. One is when the mobile node is not powered off when moving. In this case, only the lower communication control unit 5 is initialized,
The address in the new network is acquired by BOOTP or the like. Up to this point, the process is the same as described in the related art. At this time, the address held in the plural address holding unit 2 before the movement is held as it is, and the newly acquired address is added to this.

The other is a case where the mobile node is powered off when moving. Mobile node is powered off
Immediately before f, the address held by the plural address holding unit 2 is written to the local disk of the mobile node and saved. After that, when the mobile node is connected to the destination network and powered on, the mobile node stands up while acquiring a new address by the BOOTP, and sets the acquired address in the multiple address holding unit 2. After that, the address saved in the local disk of the mobile node is read and returned to the multiple address holding unit 2.

In the plural address holding unit 2, a pointer (indicating the address acquired at the time of the previous movement) is added to the address held when the address is acquired, and the addresses are connected and managed by this pointer. In this way, the multiple address holding unit 2 turns on / of the power when there is a movement.
All pre-movement addresses can be held regardless of f.

Next, the flow of processing in the case of transmission will be described. A transmission request (including transmission data, address, instructions necessary for transmission, etc.) is passed from the upper communication control unit 4 of the mobile node to the multiple address control unit 3. The multiple address control unit 3 determines whether or not the transmission source address matches the latest address (address at the current connection point), and if it matches, passes it to the lower communication control unit 5. Lower communication control unit 5
Is transmitted as a transmission packet.

If the result of determination by the plural address control unit 3 is that they do not match, the packet to be transmitted is passed to the transmission source address conversion unit 8 together with the transmission source address. The transmission source address conversion unit 8 holds the correspondence between the transmission source address and the latest address, converts the transmission source address into the latest address, and passes it to the lower communication control unit 5. The lower communication control unit 5 transmits as a transmission packet.

Next, the flow of processing in the case of reception will be described. The mobile node receives the packet by the lower communication control unit 5. The packet received by the lower communication control unit 5 is passed to the multiple address control unit 3. In the plural address control unit 3, referring to the source address conversion unit 8,
It is determined whether or not the correspondence obtained by performing the address conversion between the address designated by the application and the latest address at the time of the previous transmission is held.

If the result of determination by the plural address control unit 3 is that it is held, it is passed to the destination address conversion unit 7 for address conversion. The converted packet is passed to the upper communication control unit 4. A state in which a plurality of addresses are held in the mobile node will be described with reference to FIG. Figure 2 (a)
Shows how the mobile node holds the address in the initial state. Before moving, it just holds one as its own address, which is exactly the same as conventional communication.

In FIG. 2B, the movement is performed once,
It shows that two addresses are held. The mobile node has two addresses, an address held in the initial state and an address newly assigned in the destination network. The application apl21 continues to operate even after moving at the address adr24 that was assigned when the application started. Since the application apl22 is activated at the destination and communicates with the address adr25 at the destination, no address conversion is required and therefore the overhead is small.

In FIG. 2C, the movement is performed twice, and the movement is performed 3 times.
Shows that one address is held. Applications apl21 and apl22 continue to operate at their respective addresses adr24, adr25 when they were launched. Since the application apl23 started at the current destination is operating at the current address adr26, it does not require address translation, so the overhead is small. In this way, it is possible to perform more efficient communication as the application activated in the destination network. Furthermore, in many cases, older applications will end over time, eventually causing all applications on the mobile node to run at the latest address, resulting in a smoother new environment. Can be realized.

[0033]

As described above, according to the multi-address mobile communication device of the present invention, by holding all the addresses used for communication in the moving node, the multi-address mobile communication device is activated at the latest moving destination. For the application, there is an effect that the overhead for mobile communication can be reduced.

In addition, when the operation at the movement destination takes a long time, it is possible to gradually shift to the latest environment without making the application aware.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a multi-address communication device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which a mobile node holds a plurality of addresses.

FIG. 3 is a diagram showing a device configuration example of a mobile node in a conventional mobile communication system using a home address.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mobile communication control unit 2 Multiple address holding unit 3 Multiple address control unit 4 Upper communication control unit 5 Lower communication control unit 6 Communication line 7 Destination address conversion unit 8 Source address conversion unit

Claims (4)

[Claims] 1. A mobile communication device, which is connected to any one of connection points on a network, is assigned an address according to the connection point, and communicates via the network, wherein transmission is instructed by an application at the time of transmission. The determination means for determining whether or not the original address and the address assigned to the device at that time match, and when the determination means determines that they do not match, the source address designated by the application is set. A mobile communication device, comprising: an address conversion unit that converts an address assigned to the device. 2. A mobile communication device which is connected to any one of connection points on a network, is assigned an address according to the connection point, and communicates via the network, when receiving a packet addressed to the mobile communication device. , The judgment means for judging whether or not the packet is addressed to the application using the address currently assigned to the device, and the judgment means uses the address assigned to the device at that time. A mobile communication device comprising: an address conversion unit that converts a source address indicated by the packet into an address used by the application when it is determined that the application is not addressed to the application. 3. The mobile communication device according to claim 2, further comprising a holding unit that holds an address that can be used by an application among the addresses that were previously assigned to the device, and the address conversion unit, A mobile communication device configured to convert an address with reference to a holding unit. 4. The application uses the address assigned to the device at the time of starting the application, even after the connection point is changed.
Alternatively, the mobile communication device according to 2 or 3.