A QoS hierarchical decision scheme for vertical handoff

Next generation networks will offer services with the best quality of service (QoS) providing the users with a feeling of permanent connectivity. To that end, it is crucial to integrate heterogeneous networks so as to provide collective services. Vertical handoff consists in handing off the traffic flows of applications running on a mobile device through heterogeneous networks in order to keep or improve the QoS. In this work, we propose an algorithm for decision making in vertical handoff which considers three active applications running on a mobile device. The selectivity of our algorithm can be adjusted as a function of a set of QoS requirements e.g., the minimal bit rate, delay, jitter, and packet error rate (PER) as well as the user preferences. We show by extensive simulations that the algorithm we propose gets a significant improvement in QoS, while at the same time obtains a more efficient use of resources.