Intrusion detection in wireless networks has been a challenging research problem in network security for more than half a century. This paper presents a novel intrusion detection method based on Received Signal Strength Acceptance Test (RSSAT) to improve the IDS capabilities in anomaly-based Host-based Intrusion Detection Systems (HIDS). The new system can identify suspicious behaviors detecting anomalies in the Received Signal Strength from the access points. Several scenarios are implemented in Omnet++ environment to evaluate the performance of the proposed scheme. A test criterion is used to improve accuracy in detecting forged Signal powers and at the same time to reduce number of the false positives i.e. number of false attack alerts resulted from the legitimate Signal powers.

localization plays a significant role in lots of underwater applications. Underwater communications encounter critical challenges different from terrestrial wireless sensor networks. In this study, we focus on the challenges of the variable sound speed underwater and synchronization. Among localization approaches, the Received Signal Strength (RSS) is cost-effective and, unlike time-based approaches is synchronization-free. In some applications, the source transmitted power is unknown or hard to obtain. While this parameter is required to be known in RSS-based approaches, it is not a requirement in differential RSS (DRSS) based approaches. Regarding these issues, in this paper, we propose a DRSS-based localization algorithm considering an iso-gradient sound speed profile in an underwater medium when the source transmitted power is unknown. To improve the Received Signals’ SNR, we use a network of sensor arrays where beamforming is conducted within each array. Then, DRSS values are calculated and the iterative DRSS-based localization algorithm is presented. We show the effectiveness of the proposed algorithm compared with the Array-RSS and the Array-TDOA algorithms via computer simulations. Results indicate that the Array-DRSS performs accurately when the source transmitted power is unknown. Moreover, it outperforms the Array-TDOA algorithm when low bandwidth is available.

In this paper, we present a new method for improving the efficiency of indoor localization algorithms, in terms of running time and error rate, using the KD-tree data structure. One of the main challenges of indoor localization algorithms in large environments is the high processing overhead of these algorithms due to the high volume of input data and lack of processing resources in users' mobile devices. In the proposed method in this paper, we first cluster the fingerprint database. Then, with the help of a newly proposed method, a modified KD-tree is implemented according to the conditions of the clusters. This tree is a decision-making structure to select one specific cluster where the user stands there. Finally, when a user entered, using a few simple comparisons in the KD-tree, the desired cluster is found and only information about that cluster is passed to the localization algorithm, to compare and predict the user’s location. The results of the implementation of this method on the fingerprint data set of the Faculty of Engineering at Arak University show that the proposed method reduces the running times and errors to less than half the values, compared to the time of not using the proposed method.

In wireless channel the noise has a zero mean. This channel property can be used in the enhancement of the noise performance in the digital receivers by oversampling the Received Signal and calculating the decision variable based on the time average of more than one sample of the Received Signal. The averaging process will reduce the effect of the noise in the decision variable that will approach to the desired Signal value. The averaging process works like a filter that reduces the noise power at its output according to its averaging interval. Although the power spectrum of the noise does not change according to the averaging process, the noise variance at the decision variable will be smaller than the channel noise variance. This paper studies this idea and show how the performance of digital receivers can be enhanced by oversampling the Received Signal. This paper shows another treatment method to the noise problem in digital modulation systems.

In this paper, the existence of the interaction between the atmospheric particulate and the electromagnetic waves attenuation in the frequency band used by the 3G/4G mobile network was investigated. A few papers present in literature indicate, in presence of air pollution, the possibility of a significant cross polarization of the electromagnetic waves, while none of the papers indicated the possibility of a significant attenuation. This paper has tried to partially fill this gap of knowledge in this field with some new contributions. In all the experiments performed at the department of electrical, electronics and informatics engineering in the University of Catania (87 experiments each one lasting about 36 min), significant variations have not been found in the Received Signal level (RSL), while a polynomial dependency of the RSL local variance from the particulate concentration has been found. To demonstrate that the results obtained in the laboratory have general validity, a campaign test was conducted in an outdoors environment in the frequency band used by the 3G/4G mobile network. The site of the considered measurement station is selected to represent a typical residential area with high traffic influences in the city of Catania. Also, in this measures campaign conducted in the outdoors environment in the 3G/4G frequency band, significant variations have not been found in the RSL. While a marked dependence of the RSL local variance from the PM 10 concentration has been found. This is a noteworthy result, because certain non-negligible RSL local variance variations indicate the possibility of a pronounced cross polarization. The impact of the cross polarization becomes significant for systems reusing frequency, because the cross polarization counteracts the optimum frequency spectrum utilization.

The Analysis of radio wave propagation is a crucial part in designing an effecient wireless communication system. The Geographic information system (GIS) can be incorporated into this procedure because most of the factors in radio wave propagation are geographic features. For reliable cellular mobile communication Received Signal level must be above the receiver sensitivity. Determining of network zone in which this requirement is satisfied is done in the phase of planning of the mobile network by using various methods of  field Strength prediction. In this Paper, a system for automatic measurement of Signal level in Global System for Mobile Communication (GSM) 900/1800 MHz channel with Global Position System (GPS) localization is tested in a  field driving test carried out in Suaimania City, Kurdis-tan Region, Iraq. The result indicates that through the use of GSM, GPS and GIS (G3) technologies a map could be developed and used to study the Signal Strength of a particular location. In addition, the multipath fading phenomena effect of the mobile radio coverage could be also analyzed based on the wireless communication principles.