Delay tolerant handover for heterogeneous networks

Intermittent connectivity is one major challenge for mobile nodes that move between different networks. Existing handover procedures are able to maintain the connectivity, if the communication ranges of the networks overlap. Otherwise, the connection will be lost. This is especially problematic for e-health applications, when emergency physicians are on the way to a patient and need to stay in contact with him during the journey. Delay tolerant networks provide an option to maintain at least asynchronous communication under such conditions. But the whole network has to support the corresponding protocols, even if they are not needed in fully connected parts of the network. Therefore, we present an approach to provide handover functionality which allows nodes to switch to delay tolerant transmission seamlessly. We will discuss some conceptual aspects before presenting our solution and show the feasibility of our approach for an e-health scenario.