Physical layer aware design of network protocols and scheduling algorithms in wireless networks.

摘要

This dissertation presents various physical-layer driven scheduling algorithms and protocols for emerging wireless network technologies such as mesh networks and high-throughput LANs. Our work considers two well-known medium access categories---Time Division Multiple Access (TDMA) and Carrier Sense Multiple Access (CSMA).; We study several classes of scheduling problems in the context of stationary TDMA based mesh networks. Scheduling problems in TDMA based wireless networks have traditionally been studied using a graph-coloring approach, which abstracts away the physical layer effects. We illustrate the limitations of such an approach and present a unified framework for various classes of scheduling problems that overcomes these limitations by using a more realistic and detailed physical layer model. We demonstrate the performance improvements obtained by our scheduling techniques over prior work.; For CSMA-based systems such as high-throughput wireless LANs that use Multi-Input Multi-Output (MIMO) technology (e.g., the upcoming IEEE 802.11n standard), we present a rate adaptive medium access control protocol using transmitter antenna selection that exploits the tradeoff between spatial multiplexing and diversity to maximize achieved throughput. Our protocol employs a practical, low-overhead rate-adaptation criterion that allows the transmitter to select which antennas to use with minimal feedback from the receiver. Finally, for CSMA-based mesh networks, we present a radio aware routing protocol that seeks to find high throughput routes.