Systems and methods are disclosed for inter-system mobility in integrated LTE and trusted WLAN access networks (TWAN). An X2′ interface, adapted for both control plane and user plane communications, exists between an eNB and WLAN access point. A WLAN that has a UE attached thereto that is communicating with an EPC communicates over the X2′ interface with an C(H)eNB to handover communications from the WLAN to the (H)eNB. Similarly, an (H)eNB that has a UE attached thereto communicates over the X2′ interface with a WLAN to handover communications from the (H)eNB to the WLAN.