Mechanisms and protocol interactions for seamless handover of mobile multicast/broadcast services using unidirectional access networks in heterogeneous Mobile IP infrastructures are discussed and proposed. QoS based applications, such as content delivery, mobile TV, carousel and reliable downloads, requiring interaction channel, are considered, as well as recent standardization efforts for converged broadcast and mobile IP infrastructures. The proposed mechanisms are aimed to support handover of interactive mobile services using unidirectional broadcast media (DVB-H) combined with bidirectional mobile access technologies (UMTS, WLAN, WIMAX) in heterogeneous Mobile IPv6 environments. In particular, the focus is: - Enhancement and interactions of link layer tunnelling mechanisms (IETF RFC 3077) for provisioning of bidirectional connectivity in heterogeneous Mobile IP environment; - Access network selection and intelligent handover mechanisms based on IEEE 802.21 for services using unidir...