Analysis, design, and implementation of handover priority schemes in wireless networks.

摘要

Fast lossless handover between different networks or within the same network is one of the greatest challenges facing future wireless networks. In the first part of this thesis, we develop an analytical framework for evaluation of handover performance in 1st generation and 2nd generation networks when dynamic priority queuing of handover calls is used. This analytical framework is shown to be in excellent agreement with simulation results. This framework is comprehensive and can also cope with several priority schemes proposed by other researchers in the literature.; The second part of the thesis investigates the handover performance of existing handover priority schemes; more specifically, dynamic priority queuing and guard channel methods are compared. Practical guidelines are provided for idealistic and realistic scenarios, which can be used by cellular network operators.; In the third part of the thesis, we use a network simulator to investigate the impact of lognormal and mixed lognormal channel holding time distributions, which are the best fit to the field measurements of channel holding time, on the handover performance. Our results show that for the lognormal and mixed lognormal channel holding time distributions, the analytical results obtained under the assumption that the channel holding time follows an exponential distribution provide reasonable accuracy.; In the fourth part of the thesis, we present an analysis of multi servers with state dependent service times and prove that their performance is independent of the service time distribution under certain conditions. We also illustrate their applicability to teletraffic theory in wireless networks.; A novel system design for indoor wireless networks that use Heating, Ventilation, and Air Conditioning ducts as communication channels is described in the fifth part of the thesis. It is shown that this approach results in seamless handover and lends itself nicely to becoming a solution to coverage, capacity, and load balancing problems in indoor wireless networks.; Finally, to avoid the drastic drop in data rate when a handover occurs from high data rate networks to low data rate networks, antennas connected via gas pipes are considered for relaying the handover requests back to the high data rate network.