Patent ID: 8116775

Claim:
A method of providing user equipment (UE) with backward handover in heterogeneous wireless networks comprising the steps of: deciding the need of a handover from a serving network to a target network by the UE; initiating the backward handover by sending a handover request message to the target network through the serving network by the UE; checking capabilities of the UE and authorizing the backward handover by the serving network; preparing for the backward handover and informing the UE when preparation of the backward handover is completed by the target network; and performing handover procedure by the UE, wherein the authorizing of the backward handover comprises including a cipher key and an integrity key along with the handover request message and sending the handover request message including the cipher key and the integrity key, and wherein the preparing for the backward handover comprises generating target network specific keys from the cipher key and the integrity key.