Mobile IP communication scheme using dynamic address allocation protocol

• US 20020176383A1
• Filed: 07/01/2002
• Published: 11/28/2002
• Est. Priority Date: 02/20/1998
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Goto, Masataks, Ishiyama, Masahiro, Inoue, Atsushi, Fukumoto, Atsushi, Okamoto, Toshio, Tsuda, Yoshiyuki, Kumaki, Yoshinari
• Granted Patent: US 7,020,120 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 61/5046 Resolving address allocation conflicts; Testing of addresses testing when self-assigning an address H04L61/5092
• CPC Class Codes: H04L 61/5084 Providing for device mobility network addressing or numbering for mobility support in wireless networks H04W8/26; mobile IP H04W80/04
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04W 60/04 using triggered events
• CPC Class Codes: H04W 8/06 Registration at serving network Location Register, VLR or user mobility server
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/182 Network node acting on behalf of an other network entity, e.g. proxy

Abstract

A mobile IP communication scheme in which the mobile computer can be operated using the mobile communication protocol such as Mobile IP even in the case where the home network is operated by the dynamic address allocation protocol such as DHCP is disclosed. The current location registration message to be transmitted by the mobile computer from the visited site to the mobile computer management device contains an information indicating that the dynamic address allocation has been received at the home network and an information capable of identifying the mobile computer, and the mobile computer management device carries out exchanges with the dynamic address management server on behalf of the mobile computer, so that the mobile computer which has received the dynamic address allocation at the home network can be operated at the visited site by using the mobile communication protocol.

Claims

1. A mobile computer management device for managing a moving location information of a mobile computer which is capable of carrying out communications while moving among inter-connected networks, and transferring packets destined to the mobile computer to a current location of the mobile computer, the mobile computer management device comprising:

a reception unit for receiving a location registration message containing a first information on the current location of the mobile computer, a second information indicating that the mobile computer has received a dynamic address allocation at a home network, and a third information capable of identifying the mobile computer, from the mobile computer at a visited site outside the home network;

a transmission unit for transmitting a request message for requesting a re-allocation of a dynamic address indicated by the third information contained in the location registration message received by the reception unit, to an address management server of the home network; and

a response unit for generating a registration response message reflecting a response to the request message from the address management server, and returning the registration response message to the mobile computer.

2. The mobile computer management device of claim 1, wherein the third information is a dynamic address allocated to the mobile computer at the home network before moving.

3. The mobile computer management device of claim 1, wherein the third information is a mobile computer identifier, and the mobile computer management device further comprises a unit for retrieving a setting information of the mobile computer including a dynamic address allocated to the mobile computer at the home network before moving, according to the mobile computer identifier.

4. The mobile computer management device of claim 1, wherein the response unit generates the registration response message containing a code indicating a success of re-allocation when a re-allocation success is notified from the address management server in response to the request message.

5. The mobile computer management device of claim 1, wherein the response unit requests an allocation of another new dynamic address to the address management server and generates the registration response message containing a newly allocated dynamic address when a re-allocation failure is notified from the address management server in response to the request message.

6. The mobile computer management device of claim 5, wherein the response unit judges whether a mobile communication processing using the another new dynamic address is to be started at the mobile computer or not when the re-allocation failure is notified from the address management server in response to the request message, and generates the registration response message containing an error code without requesting the allocation of the another new dynamic address to the address management server when the mobile communication processing using the another new dynamic address is judged not to be started.

7. The mobile computer management device of claim 1, further comprising:

a proxy processing unit for receiving a message for requesting not to allocate a dynamic address allocated to the mobile computer at the home network to another computer, from the mobile computer before the mobile computer moves outside the home network, and transmitting a prescribed message for requesting not to allocate the dynamic address allocated to the mobile computer at the home network to another computer for a prescribed period of time, to the address management server.

8. The mobile computer management device of claim 1, further comprising:

a processing unit for carrying out a processing to continually reserving a dynamic address allocated to the mobile computer at the home network, at least while the mobile computer which moved outside the home network can be recognized as carrying out mobile communications via the mobile computer management device.

9. The mobile computer management device of claim 1, further comprising:

a processing unit for transmitting a notification message to notify a correspondence between a name and a new address of the mobile computer to a name management server for managing correspondences between names and addresses of computers, or causing the address management server to transmit the notification message to the name management server, when a dynamic address allocated to the mobile computer at the home network is changed.

10. A mobile computer management device for managing a moving location information of a mobile computer which is capable of carrying out communications while moving among inter-connected networks, and transferring packets destined to the mobile computer to a current location of the mobile computer, the mobile computer management device comprising:

a proxy processing unit for receiving a prescribed message from the mobile computer, and transmitting a request message for requesting not to allocate a dynamic address allocated to the mobile computer at the home network to another computer for a prescribed period of time to an address management server of the home network;

a reception unit for receiving a location registration message containing information on the current location of the mobile computer and information capable of identifying the mobile computer, from the mobile computer at a visited site outside the home network; and

a response unit for returning a response message to the mobile computer in response to the location registration message such that the mobile computer can carry out mobile communications using the dynamic address allocated to the mobile computer at the home network.

11. A mobile computer device capable of carrying out communications while moving among inter-connected networks, the mobile computer device comprising:

a transmission unit for transmitting a location registration message containing a first information on a current location of the mobile computer device, a second information indicating that the mobile computer device has received a dynamic address allocation at a home network, and a third information capable of identifying the mobile computer device, from a visited site outside the home network to a mobile computer management device provided at the home network for transferring packets destined to the mobile computer device to the current location of the mobile computer device; and

a mobile communication setting unit for receiving a response message returned from the mobile computer management device which carried out a dynamic address reallocation processing in response to the location registration message, and making a setting for mobile communications according to a response code contained in the response message.

12. The mobile computer device of claim 11, wherein the third information is a dynamic address allocated to the mobile computer device at the home network before moving.

13. The mobile computer device of claim 11, wherein the third information is a mobile computer identifier by which the mobile computer management device identifies the mobile computer device.

14. The mobile computer device of claim 11, wherein the mobile communication setting unit starts a mobile communication processing using a dynamic address allocated to the mobile computer device at the home network before moving when the response code indicates a success of the dynamic address re-allocation for the dynamic address allocated to the mobile computer device at the home network before moving.

15. The mobile computer device of claim 11, wherein the mobile communication setting unit re-initializes a communication module of the mobile computer device by using another newly allocated dynamic address when the response code indicates a failure of the dynamic address reallocation and offers the another newly allocated dynamic address.

16. The mobile computer device of claim 15, wherein the mobile communication setting unit judges whether a mobile communication processing using the another newly allocated dynamic address is to be started or not when the response code indicates the failure of the dynamic address reallocation and offers the another newly allocated dynamic address, and transmits a message for refusing the another newly allocated dynamic address to the mobile computer management device without re-initializing the communication module of the mobile computer device when the mobile communication processing using the another newly allocated dynamic address is judged not to be started.

17. The mobile computer device of claim 11, further comprising:

a request unit for transmitting a message for requesting not to allocate a dynamic address allocated to the mobile computer device at the home network to another computer for a prescribed period of time, to an address management server of the home network or the mobile computer management device, before the mobile computer device moves outside the home network.

18. The mobile computer device of claim 11, wherein the transmission unit transmits subsequent location registration messages which indicate that a dynamic address is used as a home address, regularly to the mobile computer management device after the mobile communications are started, such that the mobile computer management device continually reserve a dynamic address allocated to the mobile computer device at the home network.

19. The mobile computer device of claim 11, further comprising:

a judging unit for judging a type of communications to be carried out as either mobile communications from the visited site outside the home network through the mobile computer management device provided at the home network, or direct communications with a correspondent; and

a packet transmission unit for transmitting transmission packets by entering a dynamic address allocated to the mobile computer device at the home network into a source address of the transmission packets when the judging unit judges that the mobile communications are to be carried out, or by entering a dynamic address allocated to the mobile computer device at the visited site network into a source address of the transmission packets when the judging unit judges that the direct communications are to be carried out.

20. A mobile computer device capable of carrying out communications while moving among inter-connected networks which includes a mobile computer management device provided at a home network of the mobile computer device for transferring packets destined to the mobile computer device to a current location of the mobile computer device, the mobile computer device comprising:

a transmission unit for transmitting a message for requesting not to allocate a dynamic address allocated to the mobile computer device at the home network to another computer for a prescribed period of time, to an address management server of the home network or the mobile computer management device; and

a mobile communication unit for exchanging messages with the mobile computer management device and carrying out mobile communications using the dynamic address allocated to the mobile computer device at the home network, after the mobile computer device moved outside the home network.

21. A mobile computer device capable of carrying out communications while moving among inter-connected networks, the mobile computer device comprising:

a judging unit for judging a type of communications to be carried out as either mobile communications from a visited site outside a home network through a mobile computer management device provided at the home network for transferring packets destined to the mobile computer device to a current location of the mobile computer device, or direct communications with a correspondent; and

a packet transmission unit for transmitting transmission packets by entering a dynamic address allocated to the mobile computer device at the home network into a source address of the transmission packets when the judging unit judges that the mobile communications are to be carried out, or by entering a dynamic address allocated to the mobile computer device at the visited site network into a source address of the transmission packets when the judging unit judges that the direct communications are to be carried out.

22. A mobile computer management method for a communication system having a mobile computer which is capable of carrying out communications while moving among inter-connected networks, and a mobile computer management device provided at a home network of the mobile computer for managing a moving location information of the mobile computer and transferring packets destined to the mobile computer to a current location of the mobile computer, the mobile computer management method comprising the steps of:

receiving a location registration message containing a first information on the current location of the mobile computer, a second information indicating that the mobile computer has received a dynamic address allocation at a home network, and a third information capable of identifying the mobile computer, at the mobile computer management device from the mobile computer at a visited site outside the home network;

transmitting a request message for requesting a reallocation of a dynamic address indicated by the third information contained in the location registration message received by the receiving step, from the mobile computer management device to an address management server of the home network; and

generating a registration response message reflecting a response to the request message from the address management server, and returning the registration response message from the mobile computer management device to the mobile computer.

23. A mobile computer management method for a communication system having a mobile computer which is capable of carrying out communications while moving among networks, and a mobile computer management device provided at a home network of the mobile computer for managing a moving location information of the mobile computer and transferring packets destined to the mobile computer to a current location of the mobile computer, the mobile computer management method comprising the steps of:

receiving at the mobile computer management device a prescribed message from the mobile computer, and transmitting from the mobile computer management device a request message for requesting not to allocate a dynamic address allocated to the mobile computer at the home network to another computer for a prescribed period of time to an address management server of the home network;

receiving at the mobile computer management device a location registration message containing information on the current location of the mobile computer and information capable of identifying the mobile computer, from the mobile computer at a visited site outside the home network; and

returning a response message from the mobile computer management device to the mobile computer in response to the location registration message such that the mobile computer can carry out mobile communications using the dynamic address allocated to the mobile computer at the home network.

24. A mobile computer management method for a communication system having a mobile computer which is capable of carrying out communications while moving among networks, and a mobile computer management device provided at a home network of the mobile computer for transferring packets destined to the mobile computer to a current location of the mobile computer, the mobile computer management method comprising the steps of:

transmitting a location registration message containing a first information on a current location of the mobile computer, a second information indicating that the mobile computer has received a dynamic address allocation at a home network, and a third information capable of identifying the mobile computer, from the mobile computer a visited site outside the home network to the mobile computer management device; and

receiving at the mobile computer a response message returned-from the mobile computer management device which carried out a dynamic address re-allocation processing in response to the location registration message, and making a setting for mobile communications at the mobile computer according to a response code contained in the response message.

25. A mobile computer management method for a communication system having a mobile computer which is capable of carrying out communications while moving among networks, and a mobile computer management device provided at a home network of the mobile computer for transferring packets destined to the mobile computer to a current location of the mobile computer, the mobile computer management method comprising the steps of:

transmitting from the mobile computer a message for requesting not to allocate a dynamic address allocated to the mobile computer at the home network to another computer for a prescribed period of time, to an address management server of the home network or the mobile computer management device; and

exchanging messages with the mobile computer management device and carrying out mobile communications using the dynamic address allocated to the mobile computer at the home network, at the mobile computer after the mobile computer moved outside the home network.

26. A communication control method for a mobile computer which is capable of carrying out communications while moving among networks, the communication control method comprising the steps of:

judging a type of communications to be carried out as either mobile communications from a visited site outside a home network through a mobile computer management device provided at the home network for transferring packets destined to the mobile computer to a current location of the mobile computer, or direct communications with a correspondent; and

transmitting transmission packets by entering a dynamic address allocated to the mobile computer at the home network into a source address of the transmission packets when the judging step judges that the mobile communications are to be carried out, or by entering a dynamic address allocated to the mobile computer at the visited site network into a source address of the transmission packets when the judging step judges that the direct communications are to be carried out.

27. A computer usable medium having computer readable program code means embodied therein for causing a computer to function as a mobile computer management device for managing a moving location information of a mobile computer which is capable of carrying out communications while moving among inter-connected networks, and transferring packets destined to the mobile computer to a current location of the mobile computer, the computer readable program code means includes:

first computer readable program code means for causing said computer to receive a location registration message containing a first information on the current location of the mobile computer, a second information indicating that the mobile computer has received a dynamic address allocation at a home network, and a third information capable of identifying the mobile computer, from the mobile computer at a visited site outside the home network;

second computer readable program code means for causing said computer to transmit a request message for requesting a re-allocation of a dynamic address indicated by the third information contained in the location registration message received by the reception unit, to an address management server of the home network; and

third computer readable program code means for causing said computer to generate a registration response message reflecting a response to the request message from the address management server, and return the registration response message to the mobile computer.

28. A computer usable medium having computer readable program code means embodied therein for causing a computer to function as a mobile computer management device for managing a moving location information of a mobile computer which is capable of carrying out communications while moving among inter-connected networks, and transferring packets destined to the mobile computer to a current location of the mobile computer, the computer readable program code means includes:

first computer readable program code means for causing said computer to receive a prescribed message from the mobile computer, and transmit a request message for requesting not to allocate a dynamic address allocated to the mobile computer at the home network to another computer for a prescribed period of time to an address management server of the home network;

second computer readable program code means for causing said computer to receive a location registration message containing information on the current location of the mobile computer and information capable of identifying the mobile computer, from the mobile computer at a visited site outside the home network; and

third computer readable program code means for causing said computer to return a response message to the mobile computer in response to the location registration message such that the mobile computer can carry out mobile communications using the dynamic address allocated to the mobile computer at the home network.

29. A computer usable medium having computer readable program code means embodied therein for causing a computer to function as a mobile computer device capable of carrying out communications while moving among inter-connected networks, the computer readable program code means includes:

first computer readable program code means for causing said computer to transmit a location registration message containing a first information on a current location of the mobile computer device, a second information indicating that the mobile computer device has received a dynamic address allocation at a home network, and a third information capable of identifying the mobile computer device, from a visited site outside the home network to a mobile computer management device provided at the home network for transferring packets destined to the mobile computer device to the current location of the mobile computer device; and

second computer readable program code means for causing said computer to receive a response message returned from the mobile computer management device which carried out a dynamic address re-allocation processing in response to the location registration message, and make a setting for mobile communications according to a response code contained in the response message.

30. A computer usable medium having computer readable program code means embodied therein for causing a computer to function as a mobile computer device capable of carrying out communications while moving among inter-connected networks which includes a mobile computer management device provided at a home network of the mobile computer device for transferring packets destined to the mobile computer device to a current location of the mobile computer device, the computer readable program code means includes:

first computer readable program code means for causing said computer to transmit a message for requesting not to allocate a dynamic address allocated to the mobile computer device at the home network to another computer for a prescribed period of time, to an address management server of the home network or the mobile computer management device; and

second computer readable program code means for causing said computer to exchange messages with the mobile computer management device and carrying out mobile communications using the dynamic address allocated to the mobile computer device at the home network, after the mobile computer device moved outside the home network.

31. A computer usable medium having computer readable program code means embodied therein for causing a computer to function as a mobile computer device capable of carrying out communications while moving among inter-connected networks, the computer readable program code means includes:

first computer readable program code means for causing said computer to judge a type of communications to be carried out as either mobile communications from a visited site outside a home network through a mobile computer management device provided at the home network for transferring packets destined to the mobile computer device to a current location of the mobile computer-device, or direct communications with a correspondent; and

second computer readable program code means for causing said computer to transmit transmission packets by entering a dynamic address allocated to the mobile computer device at the home network into a source address of the transmission packets when the first computer readable program code means judges that the mobile communications are to be carried out, or by entering a dynamic address allocated to the mobile computer device at the visited site network into a source address of the transmission packets when the first computer readable program code means judges that the direct communications are to be carried out.