On access network selection models in heterogeneous networking environments

Sammanfattning: This thesis proposes and evaluates architectures and algorithms for access network selection in heterogeneous networking environments. The ultimate goal is to select the best access network at any time taking a number of constraints into account including user requirements and network characteristics. The proposed architecture enables global roaming between access networks within an operator's domain, as well as across operators without any changes in the data and control plane of the access networks being required. Also, the proposed architecture includes an algorithm for measuring performance of access networks that can be used on a number of access technologies being wired or wireless. The proposed access network selection algorithm also has an end-to-end perspective giving a network performance indication of user traffic being communicated. The contributions of this thesis include an implementation of a simulation model in OPNET Modeler, a proposal of a metric at the network layer for heterogeneous access networks, an implementation of a real-world prototype, a study of multimedia applications on perceived quality of service, an access network selection algorithm for highly mobile users and vehicular networks, and an extension of the mentioned access network selection algorithm to support cross-layer decision making taking application layer and datalink layer metrics into account.