Patent ID: 9148307
Filing Date: 2015-09-29
Classification: H04L,H04W

Abstract:
1. A method for making a handover decision in an inter Radio Access Technology (RAT) communication system, the method comprising: scanning, by a User Equipment (UE), communication of an other RAT communication system and preparing a measurement report; sending to a serving network, by the UE, the measurement report of the other RAT communication system; determining, by the serving network, a handover of the UE based on an information of the target network handover criteria and ranking information available in a network entity; sending, by the serving network, a handover request to an Inter Working Unit (IWU) in response to handover decision; converting, at the IWU, serving network specific parameters to a target specific parameter; forwarding, by the IWU, the handover request to a target network; preparing, at the target network, for handover of the UE using handover request parameters; sending, from the target network to the serving network, a handover response message; and sending a handover command to the UE to perform handover, wherein the target network computes an Integrity Key (IK), a Cipher Key (CK) and an Authentication Response (RES), and wherein the handover response message includes a Random Challenge (RAND), an Authentication Token (AUTN) and selected security parameters including a Key Set Identifier (KSI).