UC San Diego

To cope with the insatiable demand for a higher data rate in today's single channel wireless communications, extending the spectral bandwidth to transition to a multi- channel communication is a natural course of action. This dissertation, we present a wireless switching architecture that allows a self-interference-free asynchronous packet communication in multi-channel wireless switching networks. We propose a system architecture to resolve the self-interference problem, which arises due to the proximity among RF devices in the switch and the large difference in strengths between receiving and transmitting signals. We then present a straightforward solution of separating the frequency spectra used for receiving and transmitting signals and propose a MAC/PHY cross-layer protocol for efficiently managing the channel bandwidth for asynchronous packet-based communication. We show that, when a K-port wireless switch is used with each port providing 20MHz of bidirectional bandwidth, the total communication bandwidth can be increased to 1.4K x 20 MHz, which is about 2K times as high as a wireless access point with 20 MHz per channel. Of course, the actual data rate depends on the modulation schemes used. We also present a low SINR synchronization system as a physical layer solution of improving the immunity to the interference receiving from adjacent channels in a multi-channel communication environment. Finally, we introduce a scheduling scheme with a dynamic load balancing to ensure global fairness for all users. The performance of our algorithm is compared to that of the Least-Loaded-First (LLF) user assignment policy using simulations