49 research outputs found

    A Novel Handover Decision Policy for Reducing Power Transmissions in the two-tier LTE network

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    Femtocells are attracting a fast increasing interest nowadays, as a promising solution to improve indoor coverage, enhance system capacity, and lower transmit power. Technical challenges still remain, however, mainly including interference, security and mobility management, intercepting wide deployment and adoption from mobile operators and end users. This paper describes a novel handover decision policy for the two-tier LTE network, towards reducing power transmissions at the mobile terminal side. The proposed policy is LTE backward-compatible, as it can be employed by suitably adapting the handover hysteresis margin with respect to a prescribed SINR target and standard LTE measurements. Simulation results reveal that compared to the widely-adopted strongest cell policy, the proposed policy can greatly reduce the power consumption at the LTE mobile terminals, and lower the interference network-wide

    An energy-centric handover decision algorithm for the integrated LTE macrocell–femtocell network

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    Femtocells are attracting a fast increasing interest nowadays, as a promising solution to improve indoor coverage and system capacity. Due to the short transmit-receive distance, femtocells can greatly lower transmit power, prolong handset battery life, and enhance the user-perceived Quality of Service (QoS). On the other hand, technical challenges still remain, mainly including interference mitigation, security and mobility management, intercepting wide deployment and adoption by both mobile operators and end users. This paper introduces a novel energy-centric handover decision policy and its accompanied algorithm, towards minimizing the power consumption at the mobile terminal side in the integrated LTE macrocell–femtocell network. The proposed policy is shown to extend the widely-adopted strongest cell policy, by suitably adapting the handover hysteresis margin in accordance with standardized LTE measurements on the tagged user’s neighbor cells. Performance evaluation results show that significantly lower interference and power consumption can be attained for the cost of a moderately increased number of network-wide handover executions events

    Evaluation of Cryptography Usage in Android Applications

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    Mobile application developers are using cryptography in their products to protect sensitive data like passwords, short messages, documents etc. In this paper, we study whether cryptography and related techniques are employed in a proper way, in order to protect these private data. To this end, we downloaded 49 Android applications from the Google Play marketplace and performed static and dynamic analysis in an attempt to detect possible cryptographic misuses. The results showed that 87.8 % of the applications present some kind of misuse, while for the rest of them no cryptography usage was detected during the analysis. Finally, we suggest countermeasures, mainly intended for developers, to alleviate the issues identified by the analysis

    Energy Efficient Mobility Management for the Macrocell – Femtocell LTE Network

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    Femtocells will play a key role in future deployments of the 3rd Generation Partnership Project (3GPP) the Long Term Evolution (LTE) system, as they are expected to enhance system capacity, and greatly improve the energy-efficiency in a cost-effective manner. Due to the short transmit-receive distance, femtocells prolong handset battery life and enhance the Quality of Service (QoS) perceived by the end users. However, large-scale femtocell deployment comprises many technical challenges, mainly including security, interference and mobility management. Under the viewpoint of energy-efficient mobility management, this chapter discusses the key features of the femtocell technology and presents a novel energy-efficient handover decision policy for the macrocell – femtocell LTE network. The proposed HO decision policy aims at reducing the transmit power of the LTE mobile terminals in a backwards compatible with the standard LTE handover decision procedure. Simulation results show that significantly lower energy and power consumption can be attained if the proposed approach is employed, at the cost of a moderately increased number of handover executions events

    Distance Distributions and Proximity Estimation Given Knowledge of the Heterogeneous Network Layout

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    Today's heterogeneous wireless network (HWN) is a collection of ubiquitous wireless networking elements (WNEs) that support diverse functional capabilities and networking purposes. In such a heterogeneous networking environment, proximity estimation will play a key role for the seamless support of emerging applications that span from the direct exchange of localized traffic between homogeneous WNEs (peer-to-peer communications) to positioning for autonomous systems using location information from the ubiquitous HWN infrastructure. Since most of the existing wireless networking technologies enable the direct (or indirect) estimation of the distances and angles between their WNEs, the integration of such spatial information is a natural solution for robustly handling the unprecedented demand for proximity estimation between the myriads of WNEs. In this paper, we develop an analytical framework that integrates existing knowledge of the HWN layout to enable proximity estimation between WNE supporting different radio access technologies (RATs). In this direction, we derive closed-form expressions for the distance distribution between two tagged WNEs given partial (or full) knowledge of the HWN topology. The derived expressions enable us to analyze how different levels of location-awareness affect the performance of proximity estimation between WNEs that are not necessarily capable of communicating directly. Optimal strategies for the deployment of WNEs, as means of maximizing the probability of successful proximity estimation between two WNEs of interest, are presented, and useful guidelines for the design of location-aware proximity estimation in the nowadays HWN are drawn

    Automated cyber and privacy risk management toolkit

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    Addressing cyber and privacy risks has never been more critical for organisations. While a number of risk assessment methodologies and software tools are available, it is most often the case that one must, at least, integrate them into a holistic approach that combines several appropriate risk sources as input to risk mitigation tools. In addition, cyber risk assessment primarily investigates cyber risks as the consequence of vulnerabilities and threats that threaten assets of the investigated infrastructure. In fact, cyber risk assessment is decoupled from privacy impact assessment, which aims to detect privacy-specific threats and assess the degree of compliance with data protection legislation. Furthermore, a Privacy Impact Assessment (PIA) is conducted in a proactive manner during the design phase of a system, combining processing activities and their inter-dependencies with assets, vulnerabilities, real-time threats and Personally Identifiable Information (PII) that may occur during the dynamic life-cycle of systems. In this paper, we propose a cyber and privacy risk management toolkit, called AMBIENT (AutoMated cyBer and prIvacy risk managEmeNt Toolkit) that addresses the above challenges by implementing and integrating three distinct software tools. AMBIENT not only assesses cyber and privacy risks in a thorough and automated manner but it also offers decision-support capabilities, to recommend optimal safeguards using the well-known repository of the Center for Internet Security (CIS) Controls. To the best of our knowledge, AMBIENT is the first toolkit, in the academic literature, that brings together the aforementioned capabilities. To demonstrate its use, we have created a case scenario based on information about cyber attacks we have received from a healthcare organisation, as a reference sector that faces critical cyber and privacy threats
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