Effective packet scheduling with fairness adaptation in ultra wideband wireless networks

The inherent spread spectrum nature in ultrawideband (UWB) communications can support simultaneous transmissions. Two nearby transmissions do not collide, but rather generate interference to each other, thus requiring different coordination mechanisms from those in the single-channel case. This research is to design effective packet scheduling to determine when, where, and how to allow simultaneous transmissions, and how to alleviate the induced interference in order to achieve desired performance. We find out that, the exclusive region concept in the literature should be a system-level concept, taking into account interference from/to other existing active links. Based on the view, we propose the water-draining and water-adding scheduling algorithms to achieve a good compromise between throughput and fairness. Each link's achieved rate is approximately proportional to its channel quality level. The effectiveness of our proposed algorithms is validated by computer simulations.