QoS-oriented resource allocation in wireless multimedia communications

One major challenge in multimedia services over wireless networks is the quality of service (QoS) provisioning with efficient resource utilization. Compared with wired networks, heterogeneous multimedia applications in future wireless networks require a more complex QoS model and more sophisticated management of the radio resources. Due to the scarce radio spectrum, it is always desirable to meet all users' requirements and achieve high resource utilization. Thus efficient resource allocation plays an important role in this context. Many factors need to be considered in the resource allocation, such as service types, QoS requirements, and network characteristics. In this thesis, resource allocation with QoS provisioning is investigated in infrastructure-based code-division multiple access (CDMA) cellular networks and infrastructureless ultra-wideband (UWB) networks.;For UWB networks without an infrastructure, medium access control (MAC) is desired to be performed in a distributed manner. We propose a transmission frame structure for the distributed MAC tailoring to the UWB characteristics, and develop a novel control message exchange procedure. Furthermore, we propose an effective distributed admission control and resource allocation scheme to achieve high efficiency. The proposed distributed MAC can solve the near-sender-blocking problem and alleviate the negative effect of long acquisition time in UWB transmissions.;In CDMA cellular networks, we propose centralized cross-layer resource allocation schemes to provision QoS to mobile users with voice, data, or video traffic. The proposed cross-layer schemes combine the application/transport layer protocols and the link layer resource allocation to guarantee the application/transport layer QoS requirements and achieve efficient resource utilization in the link layer. Optimal resource allocation problems for voice and data traffic are formulated to guarantee pre-specified QoS with minimal required resources. For video traffic, the link layer is designed to provide the application layer with a stringent delay bound and strong protection to high priority traffic in the case of resource shortage. Acceptable level of fairness can be achieved. The proposed resource allocation can automatically adapt to multiuser diversity without many modifications.