Andreas Zalonis

Flexible-Radio: A General Framework with PHY-layer algorithm-design insights

This is a tutorial paper on the concept of flexible/reconfigurable radio systems and, especially, on the elements of flexibility residing in the PHYsical layer (PHY). It reviews past research efforts towards flexible radios and introduces the various ways in which a reconfigurable transceiver can be used to provide multi-standard capabilities, link adaptation and user/service personalization. It overviews specific tools developed within two IST projects aiming at such flexible transceiver architectures and presents a specific example of a mode-selection algorithmic architecture which incorporates all the proposed tools. Thus, it serves to illustrate a baseband version of flexibility mechanisms

On the use of radio environment maps for interference management in heterogeneous networks

This article addresses the use of REMs to support interference management optimization in heterogeneous networks composed of cells of different sizes and including both cellular and non-cellular (e.g. WiFi) technologies. After presenting a general architecture for including REM databases in different network entities, the article analyzes the achievable benefits in relation to specific interference management techniques, including a discussion on practical considerations such as information exchange requirements, REM ownership, and security aspects. Finally, several research directions derived from the proposed framework are identified.

Femtocell downlink power control based on Radio Environment Maps

The paper investigates the use of Radio Environment Maps (REMs) as a tool for Interference Management (IM) in two-tier cellular networks comprising macro- and femto-cells. The REMs are databases that provide, through different instances distributed over network elements, a variety of network- and user-related context information for improving IM and Radio Resource Management (RRM) procedures. In this context, the focus in this paper is to present the benefit of using REM information on practical power control schemes for the Femtocell downlink transmission in co-channel two-tier deployment.

Flexible radio: a framework for optimized multimodal operation via dynamic signal design

The increasing need for multimodal terminals that adjust their configuration on the fly in order to meet the required quality of service (QoS), under various channel/system scenarios, creates the need for flexible architectures that are capable of performing such actions. The paper focuses on the concept of flexible/reconfigurable radio systems and especially on the elements of flexibility residing in the PHYsical layer (PHY). It introduces the various ways in which a reconfigurable transceiver can be used to provide multistandard capabilities, channel adaptivity, and user/service personalization. It describes specific tools developed within two IST projects aiming at such flexible transceiver architectures. Finally, a specific example of a mode-selection algorithmic architecture is presented which incorporates all the proposed tools and, therefore, illustrates a baseband flexibility mechanism.

Interference management in heterogeneous wireless networks based on context information

Femtocells and WiFi have been considered as viable concepts in cellular networks to increase overall system capacity. Critical functionalities for the successful integration of such technologies in macro-cellular topologies are related to radio resource allocation and interference management techniques that must ensure seamless intra-cell and inter-cell interoperation among macro- and femto users, as well as between cellular and WiFi users. In this paper, various interference management approaches using rich context information are proposed and discussed for various scenarios of interest, along with a specific assessment for co-channel access points deployment in cellular networks.

Context-aware Radio Resource Management in HetNets

In order to address the rapid increase in data-rate requirements in existing and upcoming wireless communication systems, one solution is to add more base-stations to achieve increased spectrum reuse. A Heterogeneous Network (HetNet) - consisting of a deployment of a variety of different types of small cells in a cellular infrastructure - is one manifestation of that approach. In this HetNet case, Radio Resource Management (RRM) techniques are important to balance and optimize the radio resource allocation among users of different systems by avoiding or controlling the generated interference. This paper provides a concise description of the role of RRM techniques in HetNets by analyzing the criteria and tradeoffs that are assumed, and presents a framework for the exploitation of the available context information within the HetNet environment, that leads to optimized spectrum usage.

FLYSEC: A comprehensive control, command and Information (C2I) system for risk-based security

Increased passenger flows at airports and the need for enhanced security measures from ever increasing and more complex threats lead to long security lines, increased waiting times, as well as often intrusive and disproportionate security measures that result in passenger dissatisfaction and escalating costs. As expressed by the International Air Transport Association (IATA), the Airports Council International, (ACI) and the respective industry, todays airport security model is not sustainable in the long term. The vision for a seamless and continuous journey throughout the airport and efficient security resources allocation based on intelligent risk analysis, set the challenging objectives for the Smart Security of the airport of the future. FLYSEC, a research and innovation project funded by the European Commission under the Horizon 2020 Framework Programme, developed and demonstrated an innovative integrated and risk-based end-to-end airport security process for passengers, while enabling a guided and streamlined procedure from landside to airside and into the boarding gates, offering for the first time an operationally validated innovative concept for end-to-end aviation security. With a consortium of eleven highly specialised partners, coordinated by the National Center for Scientific Research “Demokritos,” FLYSEC developed and tested an integrated risk-based security system with a POC (Proof Of Concept) validation field trial at the Schonhagen Airport in Berlin, and a final pilot demonstration under operational conditions at the Luxembourg International Airport.

A novel architecture for behavior/event detection in security and safety management systems

In this paper the architecture of an autonomous human behavior detection system is presented. The proposed system architecture is intended for Security and Safety surveillance systems that aim to identify adverse events or behaviors which endanger the safety of people or their well-being. Applications include monitoring systems for crowded places (Malls, Mass transport systems, other), critical infrastructures, or border crossing points. The proposed architecture consists of three modules: (a) the event detection module combined with a data fusion component responsible for the fusion of the sensor inputs along with relevant high level metadata, which are pre-defined features that are correlated with a suspicious event, (b) an adaptive learning module which takes inputs from official personnel or healthcare personnel about the correctness of the detected events, and uses it in order to properly parameterise the event detection algorithm, and (c) a statistical and stochastic analysis component which is responsible for specifying the appropriate features to be used by the event detection module. Statistical analysis estimates the correlations between the features employed in the study, while stochastic analysis is used for the estimation of dependencies between the features and the achieved system performance.

DICE: Digital Immersive Cultural Environment

A Digital Immersive Cultural Environment (DICE) consists of a VR/AR (virtual & augmented reality) platform, a CMS (Content Management System) and a GIS (Geographic Information System) for geo-referencing both space and content and for providing immersive navigation in the VR/AR space. Such a platform offers 3D reconstruction of space, geo-coding of the virtual space in actual geographic coordinates and overlay capabilities with real georeferenced space. The coupling of a CMS with a GIS associates information and data with the geographic coordinates of the VR/AR space, thus making available content on demand in accordance to spatial point of interest within the VR/AR space and immersive navigation in both VR and AR spaces. Incorporation of simulation platforms, localization technologies, motion tracking technologies and VR UI’s, creates a fully interactive immersive VR/AR ecosystem, beyond the state of the art, with augmented capabilities in education, training, entertainment, content creation, etc.

FlySec: a risk-based airport security management system based on security as a service concept

Complementing the ACI/IATA efforts, the FLYSEC European H2020 Research and Innovation project (http://www.fly-sec.eu/) aims to develop and demonstrate an innovative, integrated and end-to-end airport security process for passengers, enabling a guided and streamlined procedure from the landside to airside and into the boarding gates, and offering for an operationally validated innovative concept for end-to-end aviation security. FLYSEC ambition turns through a well-structured work plan into: (i) innovative processes facilitating risk-based screening; (ii) deployment and integration of new technologies and repurposing existing solutions towards a risk-based Security paradigm shift; (iii) improvement of passenger facilitation and customer service, bringing security as a real service in the airport of tomorrow;(iv) achievement of measurable throughput improvement and a whole new level of Quality of Service; and (v) validation of the results through advanced “in-vitro” simulation and “in-vivo” pilots. On the technical side, FLYSEC achieves its ambitious goals by integrating new technologies on video surveillance, intelligent remote image processing and biometrics combined with big data analysis, open-source intelligence and crowdsourcing. Repurposing existing technologies is also in the FLYSEC objectives, such as mobile application technologies for improved passenger experience and positive boarding applications (i.e. services to facilitate boarding and landside/airside way finding) as well as RFID for carry-on luggage tracking and quick unattended luggage handling. In this paper, the authors will describe the risk based airport security management system which powers FLYSEC intelligence and serves as the backend on top of which FLYSEC’s front end technologies reside for security services management, behaviour and risk analysis.