Method of allocating an internet protocol address in a broadband wireless access system

A method of reconfiguring an internet protocol (IP) address during handover by a mobile station (MS), the method comprising:

• (a) transmitting a ranging request message to a base station (BS) in a network;
• (b) receiving from the BS in the network a ranging response message including an IP address refresh parameter which indicates whether or not IP address refreshing is required;
• and
• (c) receiving from a first entity of the network an IP address configuration response message through which an IP address is assigned, wherein the IP address configuration is attained by the first entity of the network from a second entity of the network,
• wherein the IP address refresh parameter triggers a higher layer protocol to refresh the IP address if the IP address refreshing is required, and
• a process of attaining the IP address configuration includes:
• transmitting an IP address configuration request message to the second entity of the network;
• and
• receiving an IP address configuration response message from the second entity of the network.

A method of reconfiguring an internet protocol (IP) address during handover in a network, the method comprising:

• (a) receiving by a base station (BS) a ranging request message from a mobile station (MS);
• (b) transmitting by the BS a ranging response message including an IP address refresh parameter indicating whether or not IP address refreshing is required;
• (c) receiving from the MS an IP address configuration network entity search message;
• (d) transmitting to the MS an IP address configuration network entity search result message;
• (e) receiving an IP address configuration request message from the MS;
• and
• (f) transmitting an IP address configuration response message, through which and IP address is assigned, to the MS.