Given the differences between technologies and mobility principles in 3GPP and non-3GPP access networks it is feasible to implement the mobility features between 3GPP and non-3GPP networks in a stepwise approach. This allows on one hand an early market entry of a basic solution and on the other hand a later enhancement aiming at co-operative handover decisions and context aware mobility. The latter enables a mobile node to change point of network attachment in a secure and seamless fashion.

In order to enable short term deployment of mobility over heterogeneous access networks, Mobile IPv4 and Mobile IPv6 should be introduced with some additional changes for the handover of non-real-time traffic and non-co-operative handover. In a further step, an enhanced mobility solution shall be introduced which supports a preparation phase including possible pre-authentication before the handover of the transmission path. In conjunction with this approach it is proposed to enable coordination on handover decision between the mobile node and the evolved packet core network.