Patent ID: 8774811

Claim:
A communications apparatus, comprising: a processor, coupled to a first subscriber identity card, a second subscriber identity card, a memory device and a radio transceiver module, wherein the first subscriber identity card camps on a first cell, which is associated with a first radio access technology (RAT) and belongs to a first wireless network, via the radio transceiver module; wherein the second subscriber identity card camps on a second cell, which is associated with a second RAT and belongs to a second wireless network, via the radio transceiver module; wherein the memory device stores a plurality of theoretical data transfer throughputs corresponding to different RATs; and wherein the processor constructs a first packet switch connection with the first wireless network via the first subscriber identity card to perform data transfer in the first wireless network, measures a first data transfer throughput of the first wireless network when performing the data transfer via the first subscriber identity card, obtains a theoretical data transfer throughput corresponding to the second RAT from the memory device, and determines to perform the data transfer in the second wireless network via the second subscriber identity card when the theoretical data transfer throughput corresponding to the second RAT of the second wireless network is higher than the first data transfer throughput of the first wireless network measured by the processor.