Sofoklis Kyriazakos

Admission control for QoS support in heterogeneous 4G wireless networks

Admission control plays a very important role in wireless systems, as it is one of the basic mechanisms for ensuring the quality of service offered to users. Based on the available network resources, it estimates the impact of adding or dropping a new session request. In both 2G and 3G systems, admission control refers to a single network. As we are moving towards heterogeneous wireless networks referred to as systems beyond 3G or 4G, admission control will need to deal with many heterogeneous networks and admit new sessions to a network that is most appropriate to supply the requested QoS. In this article we present the fundamentals of access-network-based admission control, an overview of the existing admission control algorithms for 2G and 3G networks, and finally give the design of a new admission control algorithm suitable for future 4G networks and specifically influenced by the objectives of the European WINNER project.

eWALL: An Intelligent Caring Home Environment Offering Personalized Context-Aware Applications Based on Advanced Sensing

Independent living of senior citizens is one of the main challenges linked to the ageing population. Senior citizens may suffer from a number of diseases, including the decline in cardiopulmonary conditions, weaker muscle functions and a declined neuromuscular control of the movements, which result in a higher risk of fall and a higher vulnerability for cardiovascular and pulmonary diseases. With respect to cognitive functions, senior citizens may suffer from a decline of memory function, less ability to orientate and a declined ability to cope with complex situations. This is by itself a big societal challenge with impact in multiple sectors. In this paper we present an innovative ICT solution, named eWALL, that aims to address these challenges by means of an advanced ICT infrastructure and home sensing environment; thus differentiating from existing eHealth and eCare solutions. The system of eWALL will extend the state-of-the-art of Assistive Platforms and will significantly increase the independent living of seniors.

eWall for Active Long Living: Assistive ICT Services for Chronically Ill and Elderly Citizens

Independent living of senior citizens is one of the main challenges linked to the ageing population, due to the impact on: (1) the life of the elderly people, (2) the national health systems, (3) the insurance companies, (4) the relatives and (5) the care-givers. Senior citizens may suffer from a number of diseases, including the decline in cardiopulmonary conditions, weaker muscle functions and a declined neuromuscular control of the movements, which result in a higher risk of fall and a higher vulnerability for cardiovascular and pulmonary diseases. With respect to cognitive functions, senior citizens may suffer from a decline of memory function, less ability to orientate and a declined ability to cope with complex situations. This paper describes work in progress and proposes a novel architecture design for eHealth services in support of independent living and compensating for prevailing age- or disease-related physical and cognitive impairments for a significant prolongation of the primary end-users functional capacity, a delay in institutionalization, increased autonomy and, prolonged participation in the society.

Visible Light Communications (VLC) for Ambient Assisted Living

With the advent of high efficacy light emitting diode directional lamps as a key component in focal lighting, new possibilities emerge for re-designing the smart home scenario. A smart home scenario is characterized by enabled intelligent interworking of various wireless and wired technologies to provide inhabitants with ease of use of appliances, while creating a personalized and safe ambience space. More and more high and low data rate circulates within the indoor ambient space (e.g., home, hospitals, offices). Although, unlicensed technologies, such as wireless local area networks can take upon part of the indoor traffic, the ever increasing demand for such data, and users, calls for either use of licensed or novel unlicensed wireless communication technologies as part of the smart home enablers. This paper focuses on the potentials of visible light communications (VLCs), jointly with radio and fiber communications, to support very dense low and high data rate connectivity, while enabling deployment of secure-sensitive indoor applications, including indoor tracking and localization. The paper proposes a scenario for integrating VLC into the smart home scenario and a conceptual supporting architecture for its deployment. Further, the technical challenges and possible roadmap for the actual deployment are analyzed for the particular case of an eHealth scenario where the utilization of VLC technology is the enabler of the cost-efficient rollout of the required infrastructure and thus the game-changer in a multi-billion eHealth niche that is seeking for cost affordable solutions.

Efficient Location-Based Hard Handoff Algorithms for Cellular Systems

Mobile world’s rapid growth has spurred development of new protocols and new algorithms to meet changing operation requirements- such as mobile networking, and quality-of-service support. Handoff is one of the most critical procedures in cellular systems. Network operators give emphasis to optimize handover, since it is strongly related to dropped calls, network overload and subsequently users’ criticism. Handoff can be seen as a blind procedure, if it is only based on the comparison of measurements, without the information of location. Since signal propagation and pathloss are complex in nature, we can expect unnecessary and wrong handoff executions. Both UMTS and those of the second generation (GSM) systems will require redefined handoff algorithms of active connections as the smooth mobility support and continuous connection are essential issues for obtaining high performance and increasing user satisfaction. In this paper we present a set of intelligent algorithms using the mobile terminal (MT) location information and area awareness to assist safe handoff decisions. The implemented algorithms are validated by means of cellular network simulators that clearly show the impact of these techniques to major system performance metrics.

BETaaS: A Platform for Development and Execution of Machine-to-Machine Applications in the Internet of Things

The integration of everyday objects into the Internet represents the foundation of the forthcoming Internet of Things (IoT). Smart objects will be the building blocks of the next generation of applications that will exploit interaction between machines to implement enhanced services with minimum or no human intervention in the loop. A crucial factor to enable Machine-to-Machine (M2M) applications is a horizontal service infrastructure that seamlessly integrates existing IoT heterogeneous systems. The authors present BETaaS, a framework that enables horizontal M2M deployments. BETaaS is based on a distributed service infrastructure built on top of an overlay network of gateways that allows seamless integration of existing IoT systems. The platform enables easy deployment of applications by exposing to developers a service oriented interface to access things (according to a Things-as-a-Service model) regardless of the technology and the physical infrastructure they belong to.

Requirements and Algorithms for Cooperation of Heterogeneous Radio Access Networks

This paper defines the requirements for cooperation of heterogeneous radio access networks (RANs) and proposes a novel radio resource management (RRM) framework for support of mobility and quality of service (QoS) in a heterogeneous communication environment comprising IMT-Advanced and legacy systems. The reference IMT-Advanced system is the one developed within the IST project WINNER (IST-2003-507581 Project Wireless Initiative New Radio, http://www.ist-winner.org). The RRM mechanisms are evolved from traditional ones to comply with the requirements imposed by a simplified new (RAN) architecture as proposed for IMT-Advanced systems. The RRM mechanisms are evaluated for the scenario of intra-RAN and inter-RAN user mobility. The RRM framework incorporates as novelty improved triggering mechanisms, a network-controlled mobility management scheme with policy enforcement on different levels in the RAN architecture, and a distributed handover and admission control mechanism for fast decision polling at different levels of the RAN. The RRM framework is further enhanced with computational intelligence based on fuzzy logic algorithms to enhance the process of handover. The RRM framework has been evaluated in terms of reduced user blocking probabilities.

Implementation of Fog computing for reliable E-health applications

This paper addresses the current technical challenge of an impedance mismatch between the requirements of smart connected object applications within the sensing environment and the characteristics of todays cloud infrastructure. We investigate the possibility to offload cloud tasks, such as storage and data signal processing to the edge of the network, thus decreasing the latency associated with performing those tasks within the cloud. The research scenario is an e-Health laboratory implementation where the real-time processing is performed by the home PC, while the extracted metadata is sent to the cloud for further processing.

Towards the Wireless 2010 Vision: A Technology Roadmap

This paper describes an envisioned technology roadmap for the development of mobile and wireless communications until the year 2010. The roadmap description is based on a 3-years study (2001–2004) and monitoring of the technological developments of characteristically chosen mobile and wireless communication areas. The final definition of the technology roadmap was based on selected areas of high value that the authors consider as the corner aspects of the evolution of mobile communications. Two main groups of areas were defined and analyzed from a technological and from a service perspective. From technological perspective the areas of high research interest include radio technologies with effect on spectrum use, access and radio interface technologies, and technologies related to mobile terminals. From service perspective, we considered interactive broadcasting, location technologies and location based services (LBS) and personalization of services. The paper identifies the open issues to be solved to realize the future of wireless communications and describes the enabling technologies for next generation communications. It identifies the technology and non-technology barriers to development, deployment, as well as guidelines for the use of technology. Finally, a visionary scenario is described to illustrate the necessary evolution of the value chain for the successful deployment of any new service or technology.

Architectures for the Provision of Position Location Services in Cellular Networking Environments

In this paper we discuss the possible position location architectures in cellular networks, their advantages and disadvantages. Localization of mobile terminals is an essential application for cellular networks. The ability to locate subscribers will give rise to developed networks, that will offer a variety of new services. Standardization groups are already investigating the possible solutions and preparing the networks for the integration of the new elements, related to localization. The recently issued FCC requirements are presented together with the current technological status. Then the candidate location-based systems, based on the generic architecture proposed by ETSI for location based services in GSM, are given. These systems are evaluated and finally a network architecture based on a hybrid positioning method is presented, which appears quite advantageous compared with the other techniques.