Mobility triggering in a multiaccess environment: Master's thesis

The services available on today’s Internet are used increasingly through heterogeneous wireless access networks and these networks use a multitude of technologies, including GPRS, UMTS, WLAN and WiMAX. Several of these networks might also be simultaneously available in overlapping areas, offering different kinds of service in terms of QoS, pricing and range. When faced with this kind of environment, the mobile terminal has to make decisions about which network it should use as an access network. Currently available mobility solutions take into account only a small subset of all the information when making their decisions on the preferred access network. In this thesis, the possible improvement of mobility management handover decision-making by cross-layer and network information is examined by building and evaluating a prototype implementation for handling mobility management in the modern multi-access environment. The prototype is built from a commercial off-the-shelf mobility solution and a prototype information collecting framework. The evaluation shows that while a commercial mobility solution did not notice lowered QoS, the prototype made handovers to the other available access networks in the same situation, which in turn significantly improved the QoS experienced. Overall, the prototype implemented in this thesis presents some ideas on improving the decision-making process of current mobility solutions and the evaluation shows that by using cross-layer and network information the QoS experienced by a mobile terminal can be significantly improved.