Patent ID: 7082130

Claim:
A method for packet data serving node redundancy in an Internet Protocol network, comprising the steps of: providing an access node comprising a plurality of N+1 packet data serving nodes and at least one system manager; selecting one packet data serving node from the N+1 packet data serving nodes as a standby; making the remaining N packet data serving nodes from the N+1 packet data serving nodes active; receiving from a radio node a registration request to establish a communication session between a packet data serving node and a mobile node; selecting an active packet data serving node; sending a registration reply message from the selected packet data serving node (PDSN) to the radio node; establishing a communication session between the mobile node and the selected PDSN; transmitting state data from the selected PDSN to the standby PDSN; periodically updating state data from the selected PDSN to the standby PDSN; and transferring the communication session to the standby PDSN upon failure of the selected PDSN.