This paper presents the results of a thorough planning investigation carried out by the Transmission System Operator (TSO) and the Distribution Network Operator (DNO) in Greece in order to study the interconnections of the Aegean Islands with the mainland power system. The feasibility of interconnecting islands is based on the need for a reliable power supply to isolated and autonomous islands, reducing the operating costs of the power generation system through the withdrawal of high-cost oil-fired generating units, and the further ability to increase renewable energy source (RES) penetration in the country’s energy mix, according to directions imposed by the National Energy and Climate Plan. Among the alternative topologies and interconnection technologies considered, the final selection of the interconnection scheme selected for inclusion in the development plans of TSO and DNO was based on their detailed comparative evaluation, considering financial and other technical criteria.

The paper presents a survey on the situation in terms of solutions for grid integration throughout the Mediterranean area in the framework of climate change and energy transition. The objective of the study is focused on Mediterranean region connectivity initiatives in the context of the broader vision of an interconnected European–Mediterranean (Euro–Med) power system for a future low-carbon energy system as the fundamental objective of Med-TSO, the Association of the Mediterranean Transmission System Operators (TSOs) for electricity. The analysis examines how the power grid connectivity evolves from now on to 2030, describing the progress made to date in integrating the power grids of the Mediterranean region as well as the future possibilities for a more integrated power grid covering the whole region. The research, conducted within Mediterranean Project II of Med-TSO, includes an overview on the current situation of the interconnections and the proposal for the 2030 interconnections Master Plan, coherent with the national development plans (NDPs) and shared energy scenarios for the whole region at the same horizon of 2030. It conducts an assessment of the gap between the current and the 2030 expected situation, taking into account the energy transition toward 2030 objectives resulting from the achievements of climate change pledges, local governmental policies and EU strategy for neighboring countries and Africa. The solutions survey includes technical solutions, procedures and rules to improve systems’ integration and increase regional electricity exchanges in Med-TSO countries, and is aimed at achieving a higher quality of services and better efficiency of energy supply in Med-TSO member countries in the framework of the expected energy transition. The main scope is to present solutions that will be made available due to maturity and experience in the coming decade, specifically: high voltage direct current (HVDC) transmission technologies, energy storage, sectors coupling, smart grid technologies and services, inter-TSO and transmission–distribution cooperation platforms, etc. The article presents two case studies: the island paradigm and a new cross-border interconnection project of common interest. Finally, the post-pandemic core role of TSOs, which has become more relevant than ever, is transformed into a key-enabler of energy transition towards a sustainable, resilient and innovative climate-neutral recovery.

The scope of this work is to present a holistic approach in quality of service (QoS) and quality of experience (QoE) characterization and prediction in modern mobile communication networks. Analytically, multi radio access technologies have been deployed in order to deliver mobile services to quality demanded consumers. Quality of Experience (QoE) parameters describe the End-to-End (E2E) quality as experienced by the mobile users. These parameters are difficult to be measured and quantified. System Quality of Service (SQoS) parameters are metrics that are closely related to the network status, and defined from the viewpoint of the service provider rather than the service user. Moreover, E2E Service Quality of Service (ESQoS) parameters describe the QoS of the services and they are obtained directly from the QoE parameters by mapping them into parameters more relevant to network operators, service providers and mobile users. A useful technique for mobile network planning and optimization is to build reliable quality estimation models for mobile voice and video telephony service.

This paper presents an experimental approach of the major data mining algorithms which can be applied to the quality prediction of provided services by contemporary mobile communication networks. Recent developments in performance evaluation of rollout mobile communication networks are based on drive-test measurement campaigns as well as on network monitoring and management systems. In addition, large measurement databases as well as data warehouses are created, updated and used for a drill-down statistics analysis. An empirical comparison of modern data mining methods for quality prediction and estimation of speech and video telephony services is presented. Learning prediction models are constructed from live network measurements which have been previously collected by experimental equipment during measurement campaigns. Practically and summing up, the proposed engineering approach is general and is applicable to various radio access network technologies during planning and optimisation phases.

Quality of experience (QoE) parameters describe the end-to-end (E2E) quality as experienced by the mobile users. These are difficult to measure and quantify. On the one hand, system quality of service (SQoS) parameters are metrics that are close related to the network status, and defined from the viewpoint of the service provider rather than the service user. On the other hand, E2E service quality of service (ESQoS) parameters describe the QoS of the services and they are obtained directly from the QoE parameters by mapping them into parameters more relevant to network operators, service providers and mobile users. A useful technique for mobile network planning and optimization is to build quality estimation models for mobile voice and video telephony service. Our research is focused on developing statistical estimation models extracted by measurements acquired via a drive-test measurement campaign of a commercial UMTS multimedia network. Regression estimates, computed with a robust optimization strategy, suggest a weaker dependence between the SQoS and ESQoS parameters and connect the strength of the dependence with the accuracy of the measurements used to compute the estimates.

The scope of this paper is to present contemporary communication aspects regarding the employment in future of smart grid as a wireless ecosystem. A wide rigorous survey on wireless access and network technologies ideal for smart grid networks is conducted, and we present applicable technologies like Internet of Things IoT and Machine-to-Machine M2M communications. Moreover, we present key topics of security, privacy and cryptography. Indeed, multimedia services will be provided in a wireless communications environment of a smart grid, while Quality of Service QoS as well as security audit shall always be crucial dimensions during a communication network modelling and planning. More specifically, the objective of our work is concentrated on the study of smart grid communications topics and security evaluation using a simulation environment and to demonstrate some interesting results.

This article presents a unified Quality of Service (QoS) prediction methodology based on neuro-fuzzy inference systems that can be used in contemporary rollout mobile communication networks. Our work is concentrated on radio key performance indicators of mobile radio access networks that affect speech and video quality of wireless multimedia communications, and on how we can estimate Quality of end-user Experience (QoE) using fuzzy-based techniques. We propose a methodology that is based on modern experimental drive-test equipment with which a measurement campaign is configured and conducted in various environments. Afterwards, ANFIS models are developed based on real network measurements and numerical results are presented.

Quality of Service (QoS) characterization and prediction is of utmost importance in contemporary operating cellular communications networks. Measurements data of speech and video telephony have been collected using modern experimental equipment. More specifically, key performance indicators of radio, speech and video quality are evoked. The objective of our study is to critically investigate the performance of speech and video telephony at live cellular networks correlating significant QoS parameters from radio and the service side. Simple non-linear regression models are also proposed for speech and video quality prediction. Finally, the paper represents the splendid positive influences of the continuous performance evaluation for the optimization of the mobile networks. There are also briefly given guidelines for mobile networks benchmarking.

Digital video broadcasting (DVB) transmission technologies are suitable for wireless delivery of multimedia content both to static and mobile end-users. On the one hand, DVB-T standard has been adopted for digital terrestrial television (DTT) and it has been further developed into a newer standard, DVB-T2, which was recently finalized. On the other hand, DVB-H is a specification for the transmission of digital TV to handheld user terminals such as smart phones delivering IP-encapsulated data. The combination of satellite and terrestrial DVB technologies is DVB-SH which delivers wide coverage to mobile terminals and promises upgraded services to mobile and vehicle users via a satellite link. The objective of our research article is to present a survey on terrestrial, mobile and hybrid DVB multimedia networks. Emphasis will be given on quality of radio and service related aspects. A focus on performance evaluation methodology based mainly on measurement campaign will be proposed with a detailed presentation of experimental equipment for drive-test field measurements. Guidelines of measurements and analysis processes will be described. A public DVB network in the area of Athens will be our case study.

The scope of this research paper is the proposal of voice quality prediction models, based on Adaptive Neuro-Fuzzy Inference Systems (ANFIS), for Adaptive Multi Rate (AMR) telephony service provided by GSM and UMTS rollout public land mobile networks. For the scope of our research we performed an experimental drive-test measurement campaign in order to evaluate objectively the End-to-End Service QoS (ESQoS) as well as radio System QoS (SQoS) parameters. Subsequently, the collected measurement data are used to train ANFIS empirical models. We then assess the prediction performance by depicting 2D/3D FIS surfaces and the impacts of SQoS to ESQoS. The prediction methodology can be successfully applied in Quality of Experience centric radio network planning, fine tuning and optimization processes by mobile operators.

Quality of service (QoS) and quality of experience (QoE) of contemporary mobile communication networks are crucial, complex and correlated.QoS describes network performance while QoE depicts perceptual quality at the user side. A set of key performance indicators (KPIs) describes in details QoS and QoE. Our research is focused specially on mobile speech and video telephony services that are widely provided by commercial UMTS mobile networks. A key point of cellular network planning and optimization is building voice and video quality prediction models. Prediction models have been developed using measurements data collected from live-world UMTS multimedia networks via drive-test measurement campaign. In this paper, we predict quality of mobile services using regression estimates inspired by the paradigm of robust optimization. The robust estimates suggest a weaker dependence than the one suggested by linear regression estimates between the QoS and QoE parameters and connect the strength of the dependence with the accuracy of the data used to compute the estimates.

The scope of our paper is to propose a methodology for QoS characterization of real world DVB networks taking into account audio-visual quality. DVB-T/H standards have been already commercially adopted for wireless terrestrial networks deployment as well as for mobile/handheld TV, while contemporary DVB-T2 and DVB-SH technologies are in research progress. Analytically, we present critical QoS(1) indicators both for radio coverage and video quality assessment. An experiment setup for DVB measurement campaign is described which is based on special laboratory equipment with diversity reception capability. Measurements analysis methods are proposed for performance evaluation and optimization as well as for benchmarking of radio broadcasting networks.

Performance evaluation of operating GSM and UMTS mobile communication networks is based usually on drivetest measurements campaign as well as on network monitoring systems. Huge measurements data-bases and data-warehouses are used for a drill-down statistics analysis. We present data mining methods for speech and video quality analysis and prediction. Quality of speech and video telephony services is proved that can be discovered applying algorithms like the k nearest neighbor classifier, decision trees and artificial neural networks. Our results suggest that, learning from QoS measurements is suitable for building evaluation and prediction models.

The rollout of multiple radio access mobile communication networks raises new challenges regarding quality of provided mobile services. Voice and video telephony are the key services that must continuously be under performance assessment and optimization. Speech and video quality in live GSM and UMTS networks are crucial performance indicators which can be measured and evaluated via drive-tests and field trials. Descriptive statistics post-processing methods of measurement data can deliver perceptual and useful conclusions to operators, either for audit or benchmarking purposes, as well as to service customers. The scope of this article is to present key performance indicators, QoS measurement equipment and comprehensive post-processing methods regarding voice and video mobile communications. An experimental measurement campaign and a drill down analysis have been performed for the purpose of the article. Finally, an approach of the public gain of QoS performance open-publishing by a telecommunications regulatory authority is carried out.

The purpose of this paper is the presentation of the wide range of applications available, that High Altitude Platform networks (HAP networks) can provide. HAP Networks have many advantages against satellites and terrestrial systems and there are also many supporting technologies/standards for the data transmission. We focus on the analysis of the new standard DVB-S2 and the possible ways that DVB-S2 can support IP services, beyond the classical Broadcast services. A crucial evaluation factor of these advantages is the key performance indicators of Quality of Service applying to possible traffic-mix scenarios. The central control unit is an adaptive radio resource management system which supports Quality of Service (QoS) and contains three main mechanisms: Buffer Management Queueing System, Call Admission Control and Congestion Control. For the inquiry of these means, a discrete event simulator based on DVB-S2 standard was developed by using OPNET Modeler. Emphasis was given to packet and frame scheduling. Thanks to the results analysis, useful conclusions were exported.