Method and system for providing interworking with portable internet network and other kinds of networks

A method for providing an inter-working function between a portable Internet system and a different type of system other than the portable Internet system, which perceives said different type of system to which a mobile communication terminal has been connected as of its connection to the portable Internet system when the mobile communication terminal connects to the portable Internet system, thereby providing a continuous communication service, the method comprising the steps of:

• (a) when the mobile communication terminal connects itself to the portable Internet system, receiving an MAC management message from the mobile communication terminal;
• (b) determining whether or not the MAC management message includes previous access network identification (PANID) for an access network of said different type of system to which the mobile communication terminal has been connected as of connection to the portable Internet system, wherein the PANID is mapped to the length of a base station identification used in the portable Internet system;
• (c) extracting PANID from MAC management message based on the determination;
• (d) selecting a Packet Data Serving Node (PDSN) of the previous access network, the connection of which is to be released, by means of the PANID;
• and
• (e) releasing connection with the PDSN of the previous access network and maintaining connection with the portable Internet system.

A system for providing an inter-working function between a portable Internet system and a different type of system other than the portable Internet system, by perceiving said different type of system to which a mobile communication terminal has been connected as of its connection to the portable Internet system when the mobile communication terminal moves and connects itself to the portable Internet system, to thereby provide a continuous communication service, the system comprising:

• the mobile communication terminal for determining if a current call is a continuous call with a previous access network of said different type of system to which the mobile communication terminal has been connected as of its connection to the portable Internet system when the mobile communication terminal connects itself to the portable Internet system, and transmitting an MAC management message including previous access network identification (PANID) when the current call is the continuous call with the previous access network, wherein the PANID is mapped to the length of a base station identification used in the portable Internet system;
• and
• an Access Control Router (ACR) of the portable Internet system for determining whether or not the MAC management message includes the PANID, extracting the PANID from the MAC management message based on the determination, and selecting a Packet Data Serving Node (PDSN) of the previous access network, the connection of which is to be released, by using the PANID, when the MAC management message is received from the mobile communication terminal via a base station of the portable Internet system.

A mobile communication terminal for providing an inter-working function between a portable Internet system and a different type of system other than the portable Internet system, by perceiving said different type of system to which the mobile communication terminal has been connected as of its connection to the portable Internet system when the mobile communication terminal moves and connects itself to the portable Internet system, to thereby provide a continuous communication service,

• wherein the mobile communication terminal determines whether a current call is a continuous call with a previous access network of said different type of system to which the mobile communication terminal has been connected as of its the connection to the portable Internet system when the mobile communication terminal connects itself to the portable Internet system, and transmits an MAC management message including previous access network identification (PANID) to a base station of the portable Internet system if the current call is the continuous call with the previous access network, wherein the PANID is mapped to the length of a base station identification used in the portable Internet system, and transmits an MAC management message not including the PANID to a base station if the current call is not the continuous call with the previous access network, thereby allowing an inter-working with the previous access network to be performed.