| With the increasing demand of wireless multimedia, future generation wide area wireless networks are faced two fundamental challenges, including efficient radio resource allocation and QoS provisioning in wireless fading environment. We focus on downlink, base stations to mobile users, since it is recognized as the bottleneck for the future.; Motivated by emerging network economics, we define the radio resource efficiency from user's point of view through users' satisfaction of received QoS, called utility function. QoS measures are signal to interference and noise ratio (SINR) for voice users, and throughput for data users. Without QoS provisioning, the best effort service is unacceptable in a deteriorative fading environment. To aid QoS provisioning, we propose different utility functions for various QoS measures, and offer both hard QoS provisioning, such as meeting voice users' SINR threshold, and soft QoS provisioning, such as achieving data users' throughput demands as close as possible. The applied control techniques include admission control, dynamic resource allocation and rate scheduling.; We start with static downlink CDMA systems with voice traffic, where radio resources are transmit power and codes. To maximize the system aggregate utility, pricing is adopted as an admission control and resource allocation policy, and optimal resource prices can be interpreted by the shadow costs associated with resource constraints and inter-cell interference. And inter-cell interference can be mitigated by transfer payments between adjacent base stations.; We then turn to dynamic downlink CDMA systems with elastic data traffic under both high mobility and low mobility with Poisson arrivals and departures. In the first dynamic system, we allow termination of ongoing users, and an empirical structure of optimal admission and termination policy is resulted. In the second dynamic system, we add time variations of fading channels to form a hierarchical two-tier problem structure, which consists of connection admission control and resource allocation (CAC-RA) in the link layer and rate scheduling in the physical layer. The cross layer architecture is dedicated for a bandwidth on demand service, and is shown to accomplish its design goal by numerical study. |
