Mac protocol design and optimization for multi-hop ultra-wideband networks

Ultra-wideband (UWB) communication is a promising enabling technology for future broadband wireless services. A simple, scalable, distributed, efficient medium access control (MAC) protocol is of critical importance to utilize the large bandwidth UWB channels and enable numerous new applications and services cost-effectively. In this paper, by investigating the characteristics of UWB communications, we propose a distributed, exclusive region (DEX) based MAC protocol. The proposed DEX protocol capitalizes on the spatial multiplexing gain of UWB networks by reserving exclusive regions (ER) surrounding the sender and receiver for data and acknowledgment (ACK) transmissions, so that users can efficiently and fairly share network resources in a distributed and asynchronous manner. We further quantify the network performance bounds and derive the optimal ER size to maximize the expected network transport throughput for a dense, multi-hop UWB network. Extensive simulation results demonstrate the efficiency and effectiveness of the DEX protocol. This work explores how to effectively utilize the wireless spatial capacity of distributed, multi-hop wireless networks by optimizing protocol parameters, instead of depending on more complicated control messages.