Resource allocation methods for quality-of-service provisioning in heterogeneous wireless networks

The increased use of mobile wireless devices that we have recently been witnessing, such as smartphones, tablets, e-readers, and WiFi enabled devices in general, is driving an unprecedented increase in the amount of data traffic. This fast market adoption of the wireless technology along with the tremendous success of multimedia applications brought about higher capacity, connectivity, and Quality of Service (QoS) requirements that can no longer be met with traditional networking paradigms. As a result, heterogeneous wireless networks have recently emerged as a potential solution for meeting such new requirements. Hybrid wireless mesh networks and femtocell/macrocell networks are examples of these newly emerging heterogeneous networks. While mesh networks are viewed as the backbone/core network, femtocell and cellular networks are viewed as the access networks linking end-users with the backbone networks. In this dissertation, we address the problem of resource allocation in heterogeneous networks. We investigate both types of networks/architectures: next-generation wireless backbone networks or simply wireless mesh networks (WMNs) and next-generation wireless access networks or simply femtocell (FC) networks. WMNs were first introduced to foster the availability of Internet services anywhere and at anytime. However, capacity limitation has been a fundamental challenge to WMNs, mainly due to the interference arising from the wireless nature of the environment as well as to the scarcity of the radio/channel resources. To overcome this problem, we propose in this dissertation an efficient scheduling scheme that reduces interference among active links via wise time and frequency assignments to the wireless mesh routers. The developed scheme is traffic aware in that it maximizes the capacity of wireless links but while accounting for their traffic loads, thus meeting the end-to-end bandwidth requirements as much as possible. In the second part of this thesis, we focus on developing power allocation techniques for FC networks. FCs have recently emerged as a key networking solution that has great potential for improving the capacity and coverage of traditional macrocell (MC) networks through high-speed indoor coverage. Their deployment, however, has given rise to new interference challenges which are mainly due to the FCs' autonomous nature and to the unreliability of the wireless medium. Driven by this fact, in the second part of this thesis, we first design a fully-distributed estimation-based power allocation scheme that aims at fairly maximizing the capacity of FC networks. Second, we propose a novel distributed stochastic power control scheme that aims at maintaining the users' minimum= required QoS. Finally, we provide cross-layer performance analysis of two-tier FC networks, in which we characterize the uplink interference and study its impact on the data-link layer QoS performance in FC networks