From the perspective of mobile users, cooperative networking solutions for heterogeneous wireless networks enable them to enjoy an always best connection. The always best connection is facilitated by internetwork vertical handoffs, which can be based on service cost, coverage, transmission rate, QoS, information security, and user preference. Taking advantage of cooperation activities among multiple access networks, internetwork vertical handoffs can be supported in a seamless and fast manner. Hence, a reliable end-to-end connection at the transport layer can be provided to preserve service continuity and minimize disruption. Also, future mobile terminals (MTs) will be equipped with multiple radio interfaces for network access. Multihoming techniques maintain multiple simultaneous associations of an MT with different radio access networks. Facilitated by cooperation across different network domains, multihoming can support applications