Network devices having handover information and method of exchanging handover information between the devices

A method of receiving and storing handover information from a handover information providing apparatus for a handover of a mobile terminal between networks, the method comprising:

• transmitting a message requesting current handover information from the handover information providing apparatus if previous handover information has been stored in a handover information storage apparatus for a predetermined period of time or longer;
• receiving a message comprising the current handover information from the handover information providing apparatus;
• and
• extracting the current handover information from the message comprising the current handover information and storing the current handover information in the handover information storage apparatus.

An information storage medium in which a data format of a message executed by a handover information providing apparatus and/or a handover information storage apparatus for exchanging handover information between the handover information providing apparatus and the handover information storage apparatus is recorded, the message comprising:

• an Internet Protocol (IP) header;
• a Transport Control Protocol (TCP) or User Datagram Protocol (UDP) header;
• a handover information message exchange header to indicate a type of an exchange of the handover information to be performed by the handover information providing apparatus and/or the handover information storage apparatus;
• and
• a handover information field including the handover information.

An information storage medium in which a data format of a message executed by a handover information providing apparatus and/or a handover information storage apparatus for exchanging handover information between the handover information providing apparatus and the handover information storage apparatus is recorded, the message comprising:

• a field indicating a type of an exchange of the handover information, wherein the type of the exchange is a transmission of handover information regarding a changed environment using a Media Independent Handover (MIH) protocol if an environment of a network of the handover information providing apparatus changes, or a request for current handover information with respect to handover information that has been stored in the handover information storage apparatus for a predetermined period of time or longer;
• a field indicating a length of the message;
• and
• a field including the handover information regarding the changed environment or the handover information that has been stored for the predetermined period of time or longer.

A system to maintain handover information for a handover of a mobile terminal between networks, the system comprising:

• a handover information providing apparatus to provide current handover information, the handover information providing apparatus comprising:
• a handover information detector to detect current handover information regarding an environment of a network of the handover information providing apparatus if the environment of the network changes, and
• a handover information transmitter to transmit a message comprising the current handover information regarding the changed environment;
• and
• a handover information storage apparatus to receive the current handover information, the handover information storage apparatus comprising:
• a handover information storage unit to store handover information,
• a message receiver to receive the message comprising the current handover information regarding the changed environment, and
• a handover information updating unit to update the handover information stored in the handover information storage unit by extracting the current handover information from the message comprising the current handover information.