Next Generation Network (NGN)-Visions of beyond third generation mobile communications describe scenarios with heterogeneous access networks and mobile devices switching between access technologies. These scenarios are either driven by network operators or motivated by the Internet-approach of loosely coupled access networks using IP as convergence layer. Both approaches lead to highly fluctuating transmission pipes that cannot be hidden from applications by Quality of Service (QoS) mechanisms in an efficient way.

My current research topic is the adaptation of application data streams. The main challenges for this are to treat scenarios with many mobile users and to evaluate the users' sense of service quality. For this purpose, mobility models and metrics for virtual transmission costs like the virtual waiting time are considered as intermediate abstractions.

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