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-multipoint 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.

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-multipoint 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.

Wireless metropolitan area networks (WMANs) based on IEEE 802.16 standard are widely deployed to provide users with wireless network connectivity, anytime, anyplace. In particular IEEE 802.16 standard has been developed to provide fixed and mobile broadband applications at lower costs for installation as compared with traditional wired infrastructures. In this paper we present the main results of a measurement campaign on propagation at 3.5 GHz conducted by BT Italy and Ericsson with the University of Rome Tor Vergata. Path loss channel model obtained from experimental data are also presented.

OFDMA/OFDM multiple access/multiplexing techniques represent the radio interface technologies for the 4-th generation broadband cellular access networks such as the WiMAX operating the point-to-multipoint configuration. In this paper we consider the problem of the frequency reuse in cellular OFDMA/OFDM systems and in particular we calculate the reuse distance which is required to obtain a given link outage probability level. Analysis is carried out using a semi-analytical approach based on a general expression of the SINR accounting for multipath, frequency and time offsets between the reference terminal and the interfering devices. The proposed approach can be easily applied to evaluate performance under different operating modes of the OFDMA/OFDM cellular network e.g. synchronous BSs or not

Wireless local area networks (WLANs) based on IEEE 802.11a standard are 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. The dependence of the channel model parameters on the tilting of the access points embedded antennas is also investigated. The developed channel models were used in a computer simulator for the optimal RF coverage inside the campus' buildings.

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.

Orthogonal multiple access/multiplexing (OFDMA/OFDM) techniques represent the radio interface technologies for the next generation broadband access networks. WiMAX system adopts them for point-to-multipoint transmission. In a typical cell radius deployment of one to tree kilometers, WiMAX systems can be expected to deliver capacity of up to 40 Mbps. However the co-channel interference due to cell frequency reuse can lead to decreasing performance. In particular, throughput and BER can get worse drastically. In this paper we deal the evaluation of interference in a WiMax cellular system. Analysis is carried out using a semi-analytical approach based on a general expression of the SINR accounting for multipath, frequency and time offsets between the reference terminal and the interfering devices. Performance have been obtained under different operating modes of the OFDMA/OFDM cellular network that is synchronous and asynchronous BSs.

The 4-th generation broadband wireless interfaces for radio access will be based on OFDMA/OFDM multiple access/multiplexing techniques. The WiMAX operating the point- to-multipoint configuration is an important example. In this paper we consider some planning issues related to the problem of the frequency reuse in cellular-like OFDMA/OFDM systems. We obtain a general expression of the SINR at the receiver (base station or terminal) accounting for multipath, frequency and time offsets between the reference receiver and the interfering devices. The proposed approach can be easily applied to evaluate performance under different operating modes of the OFDMA/OFDM cellular network e.g. synchronous BSs or not.

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 multiwall (MVV) 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.