Patent ID: 8392584

Claim:
A method for setting up a session at a Foreign Agent (FA) of a wireless communication system that uses a Mobile Internet Protocol (MIP), the method comprising: determining, by the FA, a Network Access Identifier (NAI) of a Mobile Node (MN), when at least one MN requests registration; assigning, by the FA, a session Identification (ID) to the NAI of the MN; inserting, by the FA, the session ID assigned to the NAI into an Identification Low field forming a registration request field of a message requesting registration of the MN; transmitting, by the FA, the message to a Home Agent (HA) of the MN; determining, by the FA, an MN to which registration information included in a registration reply message is to be transmitted using the session ID included in an Identification Low field forming a registration reply field of the registration reply message, when the registration reply message is received from the HA; and transmitting the registration information to the determined MN, wherein the Identification Low field comprises the session ID of the MN and time information for discriminating at least two messages comprising a same Identification High field.