Tez No	İndirme	Tez Künye	Durumu
403308		Dynamic load balancing in wireless networks / Yazar:EVŞEN YANMAZ Danışman: Prof. OZAN K. TONGUZ Yer Bilgisi: Carnegie Mellon University / Yurtdışı Enstitü Konu:Bilgisayar Mühendisliği Bilimleri-Bilgisayar ve Kontrol = Computer Engineering and Computer Science and Control ; Elektrik ve Elektronik Mühendisliği = Electrical and Electronics Engineering Dizin:	Onaylandı Doktora İngilizce 2005 189 s.
With the wide-spread deployment of wireless networks, high data rates can be provided to mobile users in large coverage areas. However, since the bandwidth in a wireless network is limited, efficient allocation of resources (channels) to each cell is crucial. This problem becomes more acute when some cells in the system are congested or "hot"; i.e., when the traffic generated by the subscribers exceeds the capacity of the service provider's infrastructure. In cellular networks, one solution to the hot spot problem is dynamically balancing the load of the hot cells, i.e., handling the excess traffic of the hot cells by the cooler (non-congested) cells in the network. In this thesis, we use an overlay ad hoc relay network over the cellular network to achieve dynamic load balancing, coverage extension, and robustness to failures and changes in the environment. We study both voice-based and voice and data based cellular networks. In the first part of the thesis, we develop a unified theoretical framework for the analysis of several key dynamic load balancing schemes proposed in the literature. This theoretical framework allows the derivation of analytical tools and closed-form expressions to study the performance of dynamic load balancing in cellular networks. The accuracy of the framework is verified for several scenarios via simulations. In the second part of the thesis, we use the developed framework to address several issues related to dynamic load balancing in wireless networks such as call blocking and handover dropping probability performance, impact of interference, performance for multiple traffic types, etc. In the third part of the thesis, we use the findings of the theoretical framework to investigat ion of an optimum dynamic load balancing scheme exists. We provide the conditions under which the key dynamic load balancing schemes can achieve optimality in terms of call blocking probability. We also propose a location dependent dynamic load balancing scheme that combines the benefits of channel borrowing and traffic forwarding based load balancing schemes. In the last part of the thesis, we shift our attention to improving the performance in voice and data-based cellular networks using relay stations in the network. In this case, we make use of relay stations not only toward Quality of Service (QoS) provisioning, but also to extend the coverage of the base transceiver stations (BTS's) and to incorporate some self-organizing features into the cellular networks. To this end, we propose topology generation and load balancing based routing algorithms for the overlay ad hoc network placed in the cellular wireless networks.