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

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

Real-Time Communications in Autonomic Networks: System Implementation and Performance Evaluation

This paper describes the design and prototype implementation of a communication platform aiming to provide voice and video communication in a distributed networking environment. Performance considerations and network characteristics have also been taken into account in order to provide the set of properties dictated by the sensitive nature and the real-time characteristics of the targeted application scenarios. The proposed system has been evaluated both by experimental means as well as subjective tests taken by an extensive number of users. The results show that the proposed platform operates seamlessly in two hops, while in the four hops scenario, audio and video are delivered with marginal distortion. The conducted survey indicates that the user experience in terms of Quality of Service has obtained higher scores in the scenario with the two hops

Hybrid Broadcast and Broadband Networks Convergence for Immersive TV Applications

This paper proposes a converged broadcast and broadband platform in order to deliver 3D media to both mobile and fixed users with guaranteed minimum Quality of Experience (QoE). The work presented offers an ideal business model for operators having both Digital Video Broadcast (DVB) and Internet Protocol (IP)-based media services. To that end, the DVB and Peer-to-Peer (P2P) Internet technologies will be combined to provide sufficient resources for supporting high-bandwidth high-quality 3D multi-view video. The motivations behind combining these technologies are outlined with an emphasis on their complementary characteristics. In addition, the overall design of the proposed architecture is presented focusing on the protocols that are exploited to achieve the interworking of the underlying technologies. Moreover, innovative key techniques for supporting both fixed and mobile users in an efficient manner are introduced