<p>A power saving method for a mobile device in a wireless communication system is disclosed. The power saving method comprises obtaining a first parameter according to a first signal transmitted between the mobile device and a first network; estimating a first power consumption of the mobile device in the first network according to the first parameter and a first radio access technology (RAT) employed in the first network; determining whether the first network is suitable according to at least a comparison of the first power consumption with a second power consumption of the mobile device in a second network, wherein the second network employs a second RAT different from the first RAT; and switching to a the second network when the first network is not suitable.</p>
