Systems and methods for controlling data traffic offload to a WLAN (e.g., a Wi-Fi network) from a WWAN (e.g., a 4G LTE network) are generally disclosed herein. One embodiment includes data traffic offload techniques managed by a Radio Resource Control (RRC) in a networked device including offloading data at the IP, PDCP, RLC, or MAC layers; another embodiment includes data traffic offload techniques managed by a MAC Scheduler with RRC control. Configurations for multimode user equipment (UE) and multimode base stations are also described herein, including configurations for implementing a Multiple Radio Access Technology (Multi-RAT) aggregation function to offload data from a WWAN to a WLAN and transmit the data via the WLAN using a Layer 2 transport.