Μηχανισμοί διαχείρισης ραδιοπόρων για σύγχρονα δίκτυα κινητών επικοινωνιών πέραν της 3ης γενιάς

Abstract

This doctoral thesis deals with mechanisms for optimal resource management in modern beyond 3G wireless networks. This research effort is based on a scalable modular structure of four axes. First, the aforementioned networks are approached through simulations in order to acquire a deep insight about their characteristics and draw valuable conclusions concerning their operation, which form the basis for further work. Second, single-carrier spread-spectrum networks are studied, focusing on the problem of serving uplink users having multiple simultaneous real-time services. As a corollary of this study, a new family of algorithms for scheduling data is introduced which meets the above requirements. Thirdly, multiple-carrier networks are investigated, which pose the demand of optimizing the management of existing resources both in the time, as well as in the frequency domain. In the context of this study, new management mechanisms that support fairness among users, coexisting heterogeneous services and various transmission and power schemes are presented. Finally, a theoretical analysis is conducted regarding the cross-layer and crosssystem optimization of wireless networks, with emphasis on the physical, the link and the transport layer. The result of this analysis is the formulation of an analytical model that expresses the relations that bind the operation and performance of the individual layers of the stack. The major findings of this work are related to mechanisms and algorithms for the effective allocation of available resources in modern beyond the 3rd and 4rd generation mobile networks.