WiMAX paves the way for wireless DSL to play a significant role in the broadband wireless access market, especially for rural areas with low population density. Conventional cellular planning methods can be used for point-to-multi-point network design. As an alternative, the Fractional Frequency Reuse (FFR) planning strategy has been recently proposed for cellular systems based on the OFDMA/OFDM radio interface (e.g., WiMAX). In this article we analyze the FFR scheme in rural areas evaluating the increase of the overall system capacity. FFR performances are reported in terms of the average number of bits that can be transmitted per symbol in the area. Finally, comparisons with classical frequency reuse planning are analyzed taking into consideration rural environment characteristics. We show that the FFR scheme can provide extra capacity, slightly penalizing the users at the cell edge. © 2008 IEEE

Wireless local area networks (WLANs) based on IEEE 802.11b standard are widely deployed to provide network connectivity without being tethered off of a wired network. An accurate planning of indoor radio networks and/or the setup of localization procedures based on IEEE 802.11 requires the characterization of the propagation channel. Starting from experimental data obtained in the campus area of the University of Rome Tor Vergata we evaluated the parameters for different multi-wall (MW) like path loss models. Differently from the standard MW model indicated in the literature, we included losses due to doors and fire proof doors that according to their status, open or closed, may lead to significant contributions to the overall attenuation. The developed channel model was used in a computer simulator for the optimal positioning of the access points inside the campus' buildings.

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The performance of networks for indoor localization based on RF power measurements from active or passive devices is evaluated in terms of the accuracy, complexity, and costs. In the active device case, the terminal to be located measures the power transmitted by some devices inside its coverage area. To determine the terminal position in the area, power measurements are then compared with the data stored in an RF map of the area. A network architecture for localization based on passive devices is presented. Its operations are based on the measure of the power retransmitted from local devices interrogated by the terminal and on their identities. Performance of the two schemes is compared in terms of the probability of localization error as a function of the number (density) of active or passive devices. Analysis is carried out through simulation in a typical office-like environment whose propagation characteristics have been characterized experimentally. Considerations obtained in this work can be easily adapted to other scenarios. The procedure used for the analysis is general and can be easily extended to other situations.

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