Sofoklis Kyriazakos

Bio: Sofoklis Kyriazakos is an academic researcher from Aarhus University. The author has contributed to research in topics: Cellular network & Handover. The author has an hindex of 16, co-authored 71 publications receiving 829 citations. Previous affiliations of Sofoklis Kyriazakos include National and Kapodistrian University of Athens & Aalborg University.

A Survey of IoT Key Enabling and Future Technologies: 5G, Mobile IoT, Sematic Web and Applications

Abstract: The Internet of Things (IoT) is the communications paradigm that can provide the potential of ultimate communication. The IoT paradigm describes communication not only human to human (H2H) but also machine to machine (M2M) without the need of human interference. In this paper, we examine, review and present the current IoT technologies starting from the physical layer to the application and data layer. Additionally, we focus on future IoT key enabling technologies like the new fifth generation (5G) networks and Semantic Web. Finally, we present main IoT application domains like smart cities, transportation, logistics, and healthcare.

Optimization of the handover algorithm based on the position of the mobile terminals

Abstract: Position location of mobile terminals is expected to be one of the key services for mobile network operators in the near future. A variety of services may be offered, such as emergency-call assistance, fleet management, location-based value added services, navigation, stolen vehicle monitoring, improved network management and differential billing. Currently, network suppliers and research institutes worldwide are trying to conclude on the integration of positioning techniques, that fulfils related FCC and ETSI localization requirements, without exaggerating network costs. Furthermore, the rapidly increasing number of mobile subscribers in addition to the introduction of new circuit/packet-based data services, will cause serious traffic overload in cellular networks. Handover procedures use the signaling resources of the network and this is one of the system's parameters that has to be optimized. We propose an intelligent algorithm that makes use of the user's location to simplify the procedure and results in a stable system, decreasing the signaling congestion and the call-drop probability.

Admission control for QoS support in heterogeneous 4G wireless networks

Abstract: 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.

Implementation of Fog computing for reliable E-health applications

Abstract: 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 today's 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.

Encyclopedia of Statistics in Behavioral Science

Abstract: An apposite and eminently readable reference for all behavioral science research and development

Signal processing techniques in network-aided positioning: a survey of state-of-the-art positioning designs

Abstract: Wireless positioning has attracted much research attention and has become increasingly important in recent years. Wireless positioning has been found very useful for other applications besides E911 service, ranging from vehicle navigation and network optimization to resource management and automated billing. Although many positioning devices and services are currently available, it is necessary to develop an integrated and seamless positioning platform to provide a uniform solution for different network configurations. This article surveys the state-of-the-art positioning designs, focusing specifically on signal processing techniques in network-aided positioning. It serves as a tutorial for researchers and engineers interested in this rapidly growing field. It also provides new directions for future research for those who have been working in this field for many years.

A Comprehensive Survey on Fog Computing: State-of-the-Art and Research Challenges

Abstract: Cloud computing with its three key facets (i.e., Infrastructure-as-a-Service, Platform-as-a-Service, and Software-as-a-Service) and its inherent advantages (e.g., elasticity and scalability) still faces several challenges. The distance between the cloud and the end devices might be an issue for latency-sensitive applications such as disaster management and content delivery applications. Service level agreements (SLAs) may also impose processing at locations where the cloud provider does not have data centers. Fog computing is a novel paradigm to address such issues. It enables provisioning resources and services outside the cloud, at the edge of the network, closer to end devices, or eventually, at locations stipulated by SLAs. Fog computing is not a substitute for cloud computing but a powerful complement. It enables processing at the edge while still offering the possibility to interact with the cloud. This paper presents a comprehensive survey on fog computing. It critically reviews the state of the art in the light of a concise set of evaluation criteria. We cover both the architectures and the algorithms that make fog systems. Challenges and research directions are also introduced. In addition, the lessons learned are reviewed and the prospects are discussed in terms of the key role fog is likely to play in emerging technologies such as tactile Internet.