Design of Mobile, Wireless (Ad Hoc) Networks Using Smart Antennas

Smart antennas, with their ability to form multiple beams of arbitrary time-varying patterns, offer the means to achieve significant performance benefits in multi-hop mobile wireless networks. The realizable gains in performance depend upon the capabilities of the antennas and the algorithms employed to control the use of their transmission resources. In our Phase I the San Diego Research Center, Inc. (SDRC) designed distributed algorithms for selecting links for packet transmissions and for scheduling and reserving transmission resources. Specifically, we developed a directional Time Division Multiple Access (TDMA) MAC algorithm (the Link Scheduling MAC, LiSL) that improves quality of service (in terms of end-to-end delay, goodput, and reliability) accorded to individual sessions, as well as the network''''''''''''''''s capacity and its ability to thwart jamming and detection by hostile entities, by equipping nodes with directional antennas. In addition, the SDRC has developed scanning techniques for blind neighbor discovery that result in low probability of detection (LPD). These techniques enable two distant nodes, with no prior knowledge of each other''''''''''''''''s relative location or direction, to find each other using narrow-beam scanning. Results of our Phase I work show that our LiSL MAC and topology management algorithms provide improvement in the capacity and latency of antenna-aware MANET. For Phase II, we propose to implement LiSL and our Topology Management algorithms, which includes our scanning neighbor discovery module. Further, we will improve the performance of our algorithms using a QualNet model of an end-to-end antenna-aware MANET. This characterization (and resultant improvement) task includes identification and exploitation of key integration points and cross-layer interactions amongst protocols at the Link, Network and Transport layers.