Wireless Network Intrinsic Secrecy

Wireless secrecy is essential for communication confidentiality, health privacy, public safety, information superiority, and economic advantage in the modern information society. Contemporary security systems are based on cryptographic primitives and can be complemented by techniques that exploit the intrinsic properties of a wireless environment. This paper develops a foundation for design and analysis of wireless networks with secrecy provided by intrinsic properties such as node spatial distribution, wireless propagation medium, and aggregate network interference. We further propose strategies that mitigate eavesdropping capabilities, and we quantify their benefits in terms of network secrecy metrics. This research provides insights into the essence of wireless network intrinsic secrecy and offers a new perspective on the role of network interference in communication confidentiality.Marie Curie International Fellowship (Grant 2010-272923)Seventh Framework Programme (European Commission) (Project CONCERTO Grant 288502)Copernicus FellowshipNational Science Foundation (U.S.) (Grant CCF-1116501)United States. Office of Naval Research (Grant N00014-11-1-0397)Massachusetts Institute of Technology. Institute for Soldier Nanotechnologie

Impact Study of Unintentional Interference on GNSS Receivers

This work has been performed in the context of an Administrative Arrangement for DG HOME. The overall scope is to perform an impact assessment of radio frequency (RF) interference on critical infrastructures relying on GNSS-services for timing and synchronization purposes. In WP3, the analysis has been divided into the impact of intentional interference on critical infrastructures presented in WP3.1 and the analysis of unintentional interference, covered in this report. DVB-T has been identied as the most important source of unintentional interference in the GNSS frequency bands and therefore a special attention is paid to this interference source. The main motivation to assess the performance reduction of receivers due to unintentional interference, is related to the high probability of these events. Unintentional interference stems from out-of-band emissions or spurious transmissions. Four different scenarios have been considered in this work, covering (i) additive white Gaussian noise, (ii) continuous wave interference, (iii) pulsed continuous wave nterference and (iv) interference that stems from the third harmonic of DVB-T transmissions. All these scenarios are highly relevant and are frequently observed in realistic signal conditions. The scenario of DVB-T interference receives most of the attention in this work, since DVB-T has become the most widely adopted digital terrestrial television broadcasting standard in the world. Harmonics of the DVB-T signal could possibly fall together with the GPS L1 or Galileo E1 bands and as such become a threat. DVB-T services are operational in more than 40 countries, with more than 75% of the deployment in Europe. In the coming years, DVB-T is expected to be deployed in more than 100 countries. In the frame of this work, different tools have been developed to quantify the impact of unintentional interference. First, a laboratory testbed has been set up, that allows to take real GPS L1 signals, combine them with synthetic interfering signals and test the robustness of different commercial and professional receivers. Further, in order to have a full control of the signal characteristics and the implementation details of the receiver, a simulation platform has been developed. This simulation tool generates GNSS as well as interfering signals, and observes consequently the impact on the acquisition or tracking performance for different receiver implementations. Finally, since it is difcult to reach statistical signicance for the acquisition performance, an analytical tool has been developed allowing to evaluate the effects of interference. This report summarises the relevant results for the four considered scenarios. For the assessment of the acquisition performance the analytical tool and the simulation platform have been used. In order to evaluate the tracking performance, experimental work has been conducted with real receivers and simulations have been performed. For the acquisition, the report quanties how much the probability of detection and the probability of false alarm are affected by the presence of interference. For the tracking, the main result of this report is the quantication of the signal degradation in terms of C=N0 and in terms of the variance of the position solution. In the scenario of DVB-T Page 2 of 94 WP3.2 interference, the degradation of the signal quality has been determined as a function of the DVB-T third harmonic power and the distance between the victim receiver and the DVB-T base station.JRC.DG.G.6-Security technology assessmen

3D Extracellular Matrix Mimics: Fundamental Concepts and Role of Materials Chemistry to Influence Stem Cell Fate

n/

A Quantitative Assessment of the Compatibility of Ultra Wideband with Broadband Wireless Access and Radar Services

In July 2008, following a request made by the Radio Spectrum Policy Unit in DG INFSO (Unit B4), a pilot phase of twelve months was agreed with Member States representatives in the Radio Spectrum Committee. During this time the Institute for the Protection and Security of the Citizen of the EC Joint Research Centre (IPSC-JRC) has been mandated to provide testing facilities to support the development of Community spectrum legal measures under the Radio Spectrum Decision (676/2002/EC). In the frame of this pilot phase, IPSC-JRC has successfully completed the implementation and extensive testing of both a state-of-the-art laboratory test-bed and a simulation tool, which have been specifically designed for two different coexistence studies. Firstly, the coexistence between broadband wireless access (BWA) and ultra wideband (UWB) services in the 3.5 GHz frequency band; and secondly, the coexistence between radiolocation (i.e. radar) and UWB services in the 3.1-3.4 GHz frequency band. The selection of these two coexistence scenarios is not casual and has been made based on the fact that they have been considered highly relevant in the CEPT-ECC studies on UWB mandated by the European Commission.JRC.G.6-Security technology assessmen

Implementation Aspects of a Transmitted-Reference UWB Receiver

In this paper, we discuss the design issues of an ultra wide band (UWB) receiver targeting a single-chip CMOS implementation for low data-rate applications like ad hoc wireless sensor networks. A non-coherent transmitted reference (TR) receiver is chosen because of its small complexity compared to other architectures. After a brief recapitulation of the UWB fundamentals and a short discussion on the major differences between coherent and non-coherent receivers, we discuss issues, challenges and possible design solutions. Several simulation results obtained by means of a behavioral model are presented, together with an analysis of the trade-off between performance and complexity in an integrated circuit implementation

Low complexity UWB receivers with ranging capabilities

Abstract This Thesis examines low complexity receiver structures for impulse-radio (IR) ultra-wideband (UWB) systems to be used in wireless sensor network applications. Such applications require radio communication solutions characterized by low cost, low complexity hardware and low power consumption to provide very long battery life. Analysis of several auto-correlation receiver (AcR) structures is performed in the presence of additive white Gaussian noise to identify receiver structures that offer a good compromise between implementation complexity and data communication performance. The classes of receiver that demonstrate the best complexity/performance trade-off are shown to be the AcR utilising transmitted-reference with binary pulse amplitude modulation signaling, and the energy detector (ED) utilising binary pulse position modulation. The analysis of these two schemes is extended to consider multipath fading channels. Numerically integrable bit error rate probability (BEP) expressions are derived in order to evaluate the receivers' performance in the presence of fading distributions characterized by closed form characteristic functions. Simulations utilising widely accepted UWB channel models are then used to evaluate the BEP in different indoor environments. Since UWB systems share frequency spectrum with many narrowband (NB) systems, and need to coexist with other UWB systems, the performance of low complexity receivers can be seriously affected by interference. In the presence of NB interference, two cases have been considered: 1) single NB interference, where the interfering node is located at a fixed distance from the receiver, and 2) multiple NB interference, where the interfering nodes are scattered according to a spatial Poisson process. When considering UWB interference, the case of multiple sources of interference has been considered. For both the multiple NB and the multiple UWB interference cases, the model derived considers several interference parameters, which can be integrated into BEP formulations for quick performance evaluations. The framework is sufficiently simple to allow tractable analysis and can serve as a guideline for the design of heterogeneous networks where coexistence between UWB systems and NB systems is of importance. The very large bandwidth of UWB signals offers an unprecedented possibility for accurate ranging operations. Signal leading-edge estimation algorithms based on average maximum likelihood estimators are derived considering different multipath channel fading distributions. Suboptimal solutions are proposed and investigated in order to support ranging capabilities in low complexity receiver structures. The ability to identify line-of-sight and non-line-of-sight conditions with the ED-based receiver is also addressed. An example of an IR-UWB low complexity transceiver based on ED for sensor network applications is proposed in this Thesis. Ad-hoc solutions for pulse transmission, synchronization and data detection are developed

Intentional network interference for denial of wireless eavesdropping

Wireless secrecy is becoming crucial in many commercial and governmental sectors. In this paper, the secrecy capacity of a wireless channel is analyzed in the presence of intentional network interference for denial of eavesdropping capability (DEC). We propose two different DEC strategies employing the closest interferer and the multiple interferers. We show the impact of the network interference on average and outage of secrecy capacity for the two DEC strategies with and without eavesdropper’s countermeasures to create a region of interference neutralization. This work provides essentials for understanding how to increase wireless secrecy using intentional network interference

Aggregate Interference in White Spaces

In this paper, we provide a comprehensive analysis of aggregated interference by opprtunistic radios accessing the white spaces of the digital television taking into account the ¿hidden node¿ problem.We propose a new statistical interference model for cognitive network in the white space context based on the amplitude aggregate interference, which accounts for the parameters related to the sensing procedure, spatial reuse protocol employed by secondary users, and environment dependent conditions like channel fading and signal obstructions. We derive the characteristic function and the nth cumulant of the cognitive network interference on the DTV receiver. Moreover, the proposed framework can help to understand secondary network interference in the TV white space context for successful coexistence between the licensed system and opportunistic networks.JRC.DG.G.6-Security technology assessmen