Empirical calculation of shadowing deviation for complex indoor propagation topologies at 2.4 GHz

Birkos

Dagiuklas

et al. 2017

Physical Communication

Self Cite

Abstract. Wireless Information-Theoretic Security (WITS) has been suggested as a robust security scheme, especially for infrastructure-less networks. Based on the physical layer, WITS considers quasi-static Rayleigh fading instead of the classic Gaussian wiretap scenario. In this paper, they key parameters of WITS are investigated by implementing an 802.11n ad-hoc network in an outdoor obstacle-dense topology. Measurements performed throughout the topology allow for a realistic evaluation of a scenario with multiple moving eavesdroppers. Low speed user movement has been considered, so that Doppler spread can be discarded. A set of discrete field test trials have been conducted, based on simulation of human mobility throughout an obstacle-constrained environment. Average Signal-to-Noise Ratio (SNR) values have been measured for all moving nodes, and the Probability of Non-Zero Secrecy Capacity has been calculated for different eavesdropping cooperative schemes (Selection Combining and Maximal-Ratio Combining). In addition, the Outage Probability has been estimated with regard to a nonzero target Secrecy Rate for both techniques. The results have been compared with the respective values of WITS key parameters derived from theoretical analysis.

Section: Average Snr Values For All Moving Nodesmentioning

confidence: 56%

Wireless Information-Theoretic Security: Theoretical analysis & experimental measurements with multiple eavesdroppers in an outdoor obstacle-dense MANET

Birkos

Dagiuklas

et al. 2017

Physical Communication

Self Cite

“…Moving past an already published comparison of the reliability of indoor path loss models, the large-scale variations of the received signal power were investigated in relation to the intrinsic characteristics of the specific environment, where the coverage area of each Access Point is significantly larger compared to standard coverage distances of 802.11g networks for indoor propagation topologies as provided in literature and also in recent published works such as [14], [15], [18], [19]. In addition, the large-scale signal fluctuation manifested a deviation from obstacle-dense indoor topologies where shadowing is a significant attenuation factor alongside (and independent from) free space, distance-dependent attenuation.…”

Section: Discussionmentioning

confidence: 99%

“…Measurements were performed extensively at Athens International Airport "Eleftherios Venizelos" throughout the airport's 802.11g network consisting of various Access Points (APs) [16]. The results provided a numerical adjustment to the ITU indoor path loss model with radically smaller values of the slope factor (path loss exponent), whereas coverage for each AP ranged up to 70 meters, marking a departure from the more limited range of APs in obstacle-dense propagation locations as in [14], [15].…”

Section: Introductionmentioning

confidence: 99%

“…These measurements served as the basis for the development and validation of an empirical method for the calculation of shadow depth (in dB) throughout an obstacledense topology, assuming a decreasing penetration loss as the number of same type of obstacles (walls, floors, materials) increases [15]. The calculation of shadow depth has allowed for a site-general characterization of large-scale fading that can be applied to any indoor topology of interest without the need for extensive on-site RF measurements, as long as losses around obstacles are provided by limited measurements.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of propagation mechanisms for the 2.4 GHz channel at Athens International Airport

2012 6th European Conference on Antennas and Propagation (EUCAP)

Kotsopoulos

2012

Self Cite

This work presents a characterization of the propagation mechanisms for the 2.4 GHz channel at Athens International Airport "Eleftherios Venizelos". Based on extensive measurements of the airport's 802.11g operating Wi-Fi network throughout the main hall of the departures level, the large-scale variations of the local mean signal power have been investigated in terms of Goodness-of-Fit provided by the Linear Polynomial and the Power Model. In addition, the values of the statistical parameters of the average received power have been calculated and compared to the classic Log-normal large-scale fading assumption. The selected measurement locations take into consideration distance-dependent propagation in a wide-area topology, and the impact of reflection and multipath phenomena. Results provide a deviation from findings in obstacle-dense indoor propagation topologies.

“…This allowed for a wireless channel characterization for home and office topologies, providing also a numerical adjustment to the original ITU specifications in [15]. In [16], an empirical method for a site-specific calculation of shadowing deviation was developed, based on the Multi-Wall-Floor (MWF) model [17].…”

Section: Introductionmentioning

confidence: 99%

Impact of shadowing on wireless channel characterization for a public indoor commercial topology at 2.4 GHz

International Congress on Ultra Modern Telecommunications and Control Systems

Georgopoulos

Kotsopoulos

2010

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This paper presents a site-specific validation of path loss models for a complex indoor propagation topology at 2.4 GHz. More specifically, extensive RF measurements were performed at the Public Library of the University of Patras (for an operating 802.11g Wi-Fi system). The acquired average received power levels allowed us to validate the robustness of indoor RF models in terms of mean error and root mean-square error (RMSE) values and compare results with empirical data derived out of other commercial topologies. The shadowing deviation was empirically calculated as a function of path loss caused by all objects and materials contributing to the attenuation of the transmitted signal. Our findings confirm that in the presence of significant shadowing phenomena and signal obstruction as examined in this work, this novel method of sitespecific calculation of shadowing deviation, which can be applied for any frequency of interest as long as the respective signal losses are empirically estimated, is by far the most precise in terms of path loss prediction and link budget optimization.