Real-Time QoS Over a Third-Generation (3G) Cellular Shared Downlink Channel

We propose a call (user) admission control (CAC) algorithm and a scheduling framework for real-time services in the third-generation (3G) and beyond cellular systems, where multiple users share a downlink packet channel in each cell. At the user or flow level, the CAC algorithm maximizes user accommodations under the QoS constraint, e.g., per-user expectation of profile rate, and the constraint of location-dependent resource availability. At the packet level, our scheduling framework, named maximum cost deduction (MCD), derives QoS-aware and channel-dependent algorithms (rt-MCD and nrt-MCD), which minimize a delay -derived cost function of backlogged packets at different timescales. The cross-layer designed CAC and MCD algorithms exploit multi-user diversity based on online measured radio resource allocation. Together they provide high system efficiency and balance between flow-level QoS, e.g. aggregate goodput and the blocking rate of newly arrived users, and packet- level QoS, e.g., the packet queueing delay or loss.