Patent ID: 7796553

Claim:
A method for performing an Inter-Radio Access Technology (RAT) handover between a Wideband Code Division Multiple Access (WCDMA) service and a Code Division Multiple Access (CDMA) service in a mobile communication device having a WCDMA modem and a CDMA modem, the method comprising: performing the WCDMA service in a WCDMA network; moving from the WCDMA network to a CDMA network; determining an Inter-RAT idle roaming to the CDMA network; measuring, with a timer, a count period from a cut-off time of the WCDMA service according to the determination of the Inter-RAT idle roaming; receiving a CDMA minimum overhead message; and performing CDMA service registration according to the Inter-RAT idle roaming before the timer is canceled if the CDMA service registration is possible according to the CDMA minimum overhead message.