Cross-Layer Scheduling of End-to-End Flows Using a Spectrum Server

We present a framework for cross-layer scheduling of end-to-end flows in a wireless network with links sharing a common spectrum. Links employ on-off modulation with fixed transmit powers when active. The data rate obtained by an active link is determined by the signal-to-interference ratio on the link. With the knowledge of the link interference gains in the network, the centralized spectrum server schedules the rates on the links and flows on the sessions to maximize a utility function of the source rates. The schedules are a collection of time shared transmission modes (sets of active links).