Binding update method, mobile terminal, home agent, and binding update system

• US 8,254,311 B2
• Filed: 10/26/2007
• Issued: 08/28/2012
• Est. Priority Date: 10/30/2006
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Morimoto, Tetsuro
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Haliyur, Venkatesh
• Application Number:
  US12/445,360
• Publication Number:
  US 20100091703A1
• Time in Patent Office: 1,768 Days
• Field of Search: 370252-474, 709241-245
• US Class Current: 370/328
• CPC Class Codes: H04W 60/005 Multiple registrations, e.g. multihoming
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

Disclosed in a technique for providing a binding update method and the like capable of resolving such a situation that a BA message keeps reciprocating between HAs. According to the technique, there is provided a binding update method, in which a mobile terminal transmits, to a home agent of the mobile terminal, a first message containing an address that is the destination to that the home agent forwards, and the home agent of the mobile terminal updates, based on the first message, a cache in which a home address of the mobile terminal is associated with an address that is the destination to that the home agent forwards, and transmits a second message as a reply to the first message to the mobile terminal, wherein when receiving the second message, the mobile terminal transmits, to the home agent of the mobile terminal, a third message notifying that the second message has been received, and after receiving the third message, the home agent of the mobile terminal updates the cache.

Claims

1. A binding update method, comprising:

transmitting, from a mobile terminal to a home agent of the mobile terminal, a first message containing a new address that is a destination to which the home agent forwards;

updating, by the home agent, based on the first message, a cache in which a home address of the mobile terminal is associated with an address to which the home agent forwards;

transmitting, from the home agent, a second message, as a reply to the first message, to the mobile terminal;

transmitting, from the mobile terminal to the home agent when receiving the second message, a third message notifying that the second message has been received, wherein

updating the cache, by home agent, occurs after receiving the third message, and

wherein the home agent of the mobile terminal sets, in the cache, a change-in-progress flag indicating that a received message is not forwarded during updating of the cache based on the first message, the home agent of the mobile terminal does not forward the received message while the change-in-progress flag is set.

2. The binding update method according to claim 1, further comprising:

adding, by the home agent, identification information to the second message, and

adding to the third message, by the mobile terminal, the identification information added to the second message.

3. A mobile terminal, comprising:

message transmitting means for transmitting messages to a home agent of the mobile terminal;

message receiving means for receiving messages from the home agent; and

message generating means for generating the messages to be transmitted to the home agent, wherein

the message generating means generates a first message containing a new address that is a destination to which the home agent forwards and the message transmitting means transmits the first message to the home agent which updates, based on the first message, a cache in which a home address of the mobile terminal is associated with an address which the home agent forwards,

the message receiving means receives a second message, transmitted by the home agent as a reply to the first message, and

the message generating means generates a third message notifying that the second message has been received when the message receiving means receives the second message and the message transmitting means transmits the third message to the home agent of the mobile terminal.

4. The mobile terminal according to claim 3, wherein when identification information is added to the second message, the message generating means adds, to the third message, the identification information added to the second message.

5. A home agent of a mobile terminal, comprising:

message generating means for generating messages to be transmitted to the mobile terminal;

message transmitting means for transmitting generated messages to the mobile terminal;

message receiving means for receiving messages transmitted by the mobile terminal; and

cache updating means for updating a cache in which a home address of the mobile terminal is associated with an address to which the home agent forwards, wherein

the message receiving means receives, from the mobile terminal, a first message containing a new address that is a destination to which the home agent forwards and the cache updating means updates the cache, based on the first message,

the message generating means generates a second message and the message transmitting means transmits the second message, as a reply to the first message, to the mobile terminal,

the message receiving means receives, from the mobile terminal, a third message notifying that the second message has been received, and

the cache updating means updates the cache when the third message is received by the message receiving means and sets, in the cache, a change-in-progress flag indicating that a received message is not to be forwarded during updating of the cache based on the first message, wherein the message transmitting means does not forward the received message while the change-in-progress flag is set.

6. The home agent according to claim 5, wherein the message generating means adds identification information to the second message.

7. A binding update system, comprising:

a mobile terminal; and

a home agent of the mobile terminal, wherein

the mobile terminal is configured to transmit, to the home agent, a first message containing a new address that is a destination to which the home agent forwards,

the home agent is configured to update, based on the first message, a cache in which a home address of the mobile terminal is associated with an address to which the home agent forwards and to transmit a second message, as a reply to the first message, to the mobile terminal,

the mobile terminal is further configured to transmit, when receiving the second message, a third message notifying that the second message has been received, and

after receiving the third message, the home agent updates the cache,

wherein the home agent of the mobile terminal sets, in the cache, a change-in-progress flag indicating that a received message is not forwarded during updating of the cache based on the first message, the home agent of the mobile terminal does not forward the received message while the change-in-progress flag is set.

8. The binding update system according to claim 7, wherein

the home agent of the mobile terminal adds identification information to the second message, and

the mobile terminal adds, to the third message, the identification information added to the second message.