A unified architecture for adaption of mobile system behaviour: implementation of the vertical handoff paradigm.
Doctoral thesis, UCL (University College London).
Independent attempts from the computing and telecommunications worlds to provide wireless access resulted in networks with very different characteristics. This has given rise to a number of issues, such as the management of user mobility, power consumption, contingency when a communication session is interrupted etc. The result is significant Quality of Service fluctuation. A particular issue arises in an environment where more than one wireless networks offer coverage over the same area making the decision about which network to connect to, rather complex. The thesis offers the hypothesis that a unified architecture can meet the current QoS demands of qos-sentitive applications. It provides the framework that can effectively include, activate, configure and orchestrate disparate communication enhancement tools. The architecture must be extensible, flexible, and provide means for the incorporated modules to interoperate. Finally, it must allow the QoS requirements to be specified in platform independent ways and QoS adaptation to be effected under application, application manager, or user control in a continuous and dynamic way. The Vertical Handoff paradigm is studied as an illustration of a communication enhancement module of this architecture. Consider a two layer wireless network. Layer one offers high bandwidth but short-range coverage, while layer two offers low bandwidth but wide range coverage. A mobile host moving fast will experience high bandwidth with frequent handovers when connected to layer one or low bandwidth with fewer handover interruptions if connected to the bigger cells of layer two. This and other scenarios are studied in this research in order to test the hypothesis that the use of local and/or network cache can result in significant performance enhancement in terms of frequency of interruptions due to handovers and overall quality of the communication’s service depending on factors such as the host’s mobility, the population density, etc.
|Title:||A unified architecture for adaption of mobile system behaviour: implementation of the vertical handoff paradigm|
|Additional information:||Authorisation for digitisation not received|
Archive Staff Only