Quality of Service Provisioning in Wireless Networks

Wireless scheduling plays an important role in the design of advanced wireless networks as it determines the QoS provisioning over the wireless link. Compared to its wired counterpart, the design of wireless schedulers is a much harder and challenging problem due to the unique characteristics of the wireless channel. While recent work focused on the design of wireless schedulers to meet a given performance objective, our research aims to characterize the QoS performance of a generic wireless scheduler in a downlink centralized scheduling scenario. We characterize each input flow in terms of its time-fraction requirement (the fraction of resources that it should be allocated) and its channel agility (the likelihood of transition from one channel state to another across successive time slots). These parameters characterize each class in a class-based scheduling scenario. We define a channel-independent scheduler that aggregates all the input flows prior to scheduling, and a generic channel-state dependent wireless-fair scheduler that can be abstracted into various functional components. In particular, the slot allocation policy determines the QoS performance of the wireless-fair scheduler under error-free conditions. We analyze the allocation periodicity of perfectly-fair (i.e., allocated share = time-fraction requirement) loop schedulers, based on which we propose a recursive implementation. On the other hand, the arbitration scheme selects a flow for transmission in