Simulation System for Performance Evaluation of Autonomous Distributed Wireless Ad Hoc Information Networks

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With a recent trend to embed huge number of wireless transceiver chips to every device and equipment in daily life, study of an autonomous distributed wireless ad hoc networking is getting more and more important. A flexible simulation system for the performance evaluation of such autonomous wireless networks has been implemented to study fundamental problems indispensable for its design, such as spectrally efficient relaying scheme, routing issue and location management. Major research results obtained through the project are summarized below.1. Spectral efficiency and terminal power consumption of ad hoc networks were studied and compared with those of cellular system. We found that an optimum hop distance exists assuring the maximum number of simultaneous routes, and power consumption is comparable to the cellular system.Routing scheme is modified so that it is applicable to the non-uniform terminal distribution case.2. A hierarchical routing protocol for ad hoc networks has been proposed and its performance has been evaluated by computer simulations. It is based on CBRP (Cluster Based Routing Protocol) and finds more robust routes by utilizing location and velocity information.3. A destination discovery scheme has been proposed assuming a city-wide wireless multi-hop network and its performance has been evaluated by computer simulations. A mobile station tries to find its destination using the location information, which is collected and kept by sparsely scattered simple fixed stations.4. An experimental multi-hop network consisting of notebook PC's is implemented using IEEE802. 11b wireless LAN cards and its throughput is evaluated. By reducing the transmitter power and introducing multi-hop connection, total throughput is found to increase owing to the spatial frequency reuse.