Patent ID: 8391211

Claim:
A method for handling data transmission by a mobile station with a first radio frequency (RF) module coupled to a first subscriber identity card and a second RF module coupled to a second subscriber identity card, comprising: assigning the first RF module to transmit a first packet originally having a source IP address IP(U) and a destination IP address IP(Y) corresponding to an access network; replacing the source IP address IP(U) of the first packet with a source IP address IP(A) corresponding to the first RF module; assigning the second RF module to transmit a second packet originally having the source IP address IP(U) and the destination IP address IP(Y); replacing the source IP address IP(U) of the second packet with a source IP address IP(B) corresponding to the second RF module; transmitting the replaced first packet using the first subscriber identity card to the access network via the first RF module and the replaced second packet using the second subscriber identity card to the access network via the second RF module; further comprises receiving a first response packet and a second response packet; wherein the first response packet is received from the access network by the first RF module, wherein the first response packet has the source IP address IP(Y) and the destination IP address IP(A); replacing the destination IP address IP(A) of the response packet with the destination IP address IP(U); wherein the second response packet is received from the access network by the second RF module, wherein the second response packet has the source IP address IP(Y) and a destination IP address IP(B); and replacing the destination IP address IP(B) of the response packet with the destination IP address IP(U).