Patent ID: 8792365

Claim:
A method for inter-radio access technology (inter-RAT) handover, comprising: determining a quality of a signal from at least one first target RAT for an intra-RAT handover, while a user equipment (UE) is currently served by a source RAT, when a quality of a signal from the source RAT is less than a threshold, the at least one first target RAT being of a same RAT type as the source RAT; transmitting, to the source RAT, the quality of the signal from the at least one first target RAT; receiving, from the source RAT, instructions to determine a quality of signals from a plurality of second target RATs when the quality of the signal from the at least one first target RAT is less than a threshold, the second target RATs being of a different RAT type than the source RAT; determining the quality of signals from the plurality of second target RATs while the UE is currently served by the source RAT; transmitting, to the source RAT, an indication of the determined quality of the signals for the plurality of second target RATs; and handing over the call to one of the plurality of second target RATs based upon a service type of the call.