Data forwarding controller, communication terminal apparatus, data communication system and method, and computer program for performing handover for a mobile node

1. A mobile communication terminal apparatus which performs data transmission/reception via a network and which changes access points based on data receiving conditions, the apparatus comprising:

an acquisition device configured to acquire a MAC address of a next access point to which said communication terminal apparatus is scheduled to be connected next after a handover from a current access point, and broadcast a handover start message containing said acquired MAC address of said next access point, and

a handover device configured to perform a handover process on condition that said communication terminal apparatus receives a handover setting completion message from a data forwarding controller as a response to said handover start message, and

said communication terminal apparatus is configured to perform a background scanning process by which all wireless channels are periodically scanned, to acquire and store a source MAC address of a received beacon as said MAC address of said next access point.

2. The mobile communication terminal apparatus according to claim 1 , wherein said communication terminal apparatus is configured to re-transmit said handover start message for a time period from transmission of said handover start message to reception of said handover setting completion message.

3. The mobile communication terminal apparatus according to claim 1 , wherein said communication terminal apparatus is configured to transmit to said data forwarding controller from which said handover setting completion message is received or broadcast, a handover end message containing a MAC address of an old access point which said communication terminal apparatus has disconnected, after said handover process has been performed.

4. A method of performing a handover process on a mobile communication terminal apparatus which performs data transmission/reception via a network and which changes access points based on data receiving conditions, said method comprising:

acquiring a MAC address of a next access point to which said communication terminal apparatus is scheduled to be connected next, the acquiring including performing a background scanning process by which all wireless channels are periodically scanned, to acquire and store a source MAC address of a received beacon as said MAC address of said next access point;

broadcasting a handover start message containing said acquired MAC address of said next access point; and

performing said handover process on condition that a handover setting completion message is received from a data forwarding controller as a response to said handover start message.

5. The method according to claim 4 , further comprising:

re-transmitting said handover start message for a time period from transmission of said handover start message to reception of said handover setting completion message.

6. The method according to claim 4 , further comprising:

transmitting to said data forwarding controller from which said handover setting completion message is received or broadcasting, a handover end message containing a MAC address of an old access point which said communication terminal apparatus has disconnected, after said handover process has been performed.

7. A non-transitory computer readable medium including computer executable instructions, wherein the instructions, when executed by a processor, cause the processor to perform a method for executing a handover process on a computer system performed by a mobile communication terminal apparatus which performs data transmission/reception via a network and which changes access points based on data receiving conditions, said method comprising:

acquiring a MAC address of a next access point to which said communication terminal apparatus is scheduled to be connected next, the acquiring including performing a background scanning process by which all wireless channels are periodically scanned, to acquire and store a source MAC address of a received beacon as said MAC address of said next access point;

broadcasting a handover start message containing said acquired MAC address of said next access point; and

performing said handover process on condition that a handover setting completion message is received from a data forwarding controller as a response to said handover start message.

8. A mobile communication terminal apparatus which performs data transmission/reception via a network and which changes access points based on data receiving conditions, the apparatus comprising:

an acquisition unit configured to acquire a MAC address of a next access point to which said communication terminal apparatus is scheduled to be connected next after a handover from a current access point, and broadcast a handover start message containing said acquired MAC address of said next access point, and

a handover unit configured to perform a handover process on condition that said communication terminal apparatus receives a handover setting completion message from a data forwarding controller as a response to said handover start message, and

said communication terminal apparatus is configured to perform a background scanning process by which all wireless channels are periodically scanned, to acquire and store a source MAC address of a received beacon as said MAC address of said next access point.