1. A method, comprising: activating a first network interface of a user equipment (UE) for transmitting and receiving IP data through a first radio access technology (RAT) in a heterogeneous network; activating a second network interface for transmitting and receiving IP data through a second RAT; determining a traffic flow distribution based on one or more predefined criteria, wherein the traffic flow is associated with one or more applications; and directing a first portion of the traffic flow to the first network interface, and directing a second portion of the traffic flow to the second network interface.