Designing an innovative educational toolbox to support the transition to new technologies

Our economies and societies are becoming more and more knowledge based which implies that increasing numbers of people need to be educated and trained on new subjects and processes. Thus, the reduction of the effort needed to design and prepare educational and training programmes that meet the needs of the society and the market is of paramount importance. To achieve this goal, first, we define a learning programme model so that programme designers can easily exchange and re-use programme structures and learning materials. The proposed model additionally enables easier creation of interdisciplinary programmes which is another need of today’s market. Second, we deploy a web-based tool that adopts this model towards facilitating the re-use of structures and materials. Third, to reduce the time required for the training actors to sense the market needs, we propose the establishment of an educational programme marketplace. All three endeavours have been validated in the energy transition sector and (positively) evaluated by experts during an international workshop

Extreme Level Crossing Rate: A New Performance Indicator for URLLC Systems

Level crossing rate (LCR) is a well-known statistical tool that is related to the duration of a random stationary fading process \emph{on average}. In doing so, LCR cannot capture the behavior of \emph{extremely rare} random events. Nonetheless, the latter events play a key role in the performance of ultra-reliable and low-latency communication systems rather than their average (expectation) counterparts. In this paper, for the first time, we extend the notion of LCR to address this issue and sufficiently characterize the statistical behavior of extreme maxima or minima. This new indicator, entitled as extreme LCR (ELCR), is analytically introduced and evaluated by resorting to the extreme value theory and risk assessment. Capitalizing on ELCR, some key performance metrics emerge, i.e., the maximum outage duration, minimum effective duration, maximum packet error rate, and maximum transmission delay. They are all derived in simple closed-form expressions. The theoretical results are cross-compared and verified via extensive simulations whereas some useful engineering insights are manifested.Comment: Accepted for publication in IEEE TV

Scalable monitoring for multiple virtualized infrastructures for 5G services

This paper presents a high level architecture and functionality details of the monitoring framework that has been implemented and integrated within the SONATA project, in order to support the management of 5G services under the Software Defined Networking / Network Function Virtualization (SDN/NFV) paradigm. The innovative framework, extending the functionality of Prometheus.io, is unique in its support for multiple Points of Presence (PoP), its extensibility using Websockets, and its availability as opensource

An artificial intelligence-based collaboration approach in industrial IoT manufacturing : key concepts, architectural extensions and potential applications

The digitization of manufacturing industry has led to leaner and more efficient production, under the Industry 4.0 concept. Nowadays, datasets collected from shop floor assets and information technology (IT) systems are used in data-driven analytics efforts to support more informed business intelligence decisions. However, these results are currently only used in isolated and dispersed parts of the production process. At the same time, full integration of artificial intelligence (AI) in all parts of manufacturing systems is currently lacking. In this context, the goal of this manuscript is to present a more holistic integration of AI by promoting collaboration. To this end, collaboration is understood as a multi-dimensional conceptual term that covers all important enablers for AI adoption in manufacturing contexts and is promoted in terms of business intelligence optimization, human-in-the-loop and secure federation across manufacturing sites. To address these challenges, the proposed architectural approach builds on three technical pillars: (1) components that extend the functionality of the existing layers in the Reference Architectural Model for Industry 4.0; (2) definition of new layers for collaboration by means of human-in-the-loop and federation; (3) security concerns with AI-powered mechanisms. In addition, system implementation aspects are discussed and potential applications in industrial environments, as well as business impacts, are presented

Design, development and implementation of trust and energy-aware routing Protocols in wireless sensor networks

Wireless Sensor Networks (WSNs) appeared almost two decades ago and from that time they have witnessed a tremendous bloom. Their application domains proliferate, ranging from environmental sensing and health care monitoring to military purposes; this is attributed to their unique advantages, such as low cost, wireless infrastructure-less operation, easy installation, etc. This application expansion (which implies analogous sensor population expansion) made the designers of Future Internet to consider WSNs as a valuable source of real-time information that can be exploited to improve the user experience, thus bringing WSN in the Future Internet scene. Despite their popularity, WSNs come with specific intricacies: the sensor nodes are characterized by limited processing, memory, communication and energy resources since they are usually battery-operated. Furthermore, in order to support self-organization, routing has to be performed in a cooperative manner, making them vulnerable to significant security threats. These intricacies have mandated the design of novel routing protocols that suit the needs of the application at hand, addressing the security implications by the introduction of novel trust management schemes to mitigate routing attacks, while simultaneously adopting strategies for energy-efficiency to prolong the network lifetime. In this Ph.D. thesis, we address the aforementioned issues by designing novel routing solutions that combine pure routing information with trust and energy information, satisfying the requirements of modern WSNs, which have to support multiple (and even diverse) applications with different Quality of Service requirements, nodes mobility and high node density. In the following, we present two trust and energy-aware routing solutions: The ambient trust secure routing algorithm is based on the geographical routing principles and very-well fits the requirements of mobility and large-scale WSN deployments, while being capable of mitigating a plethora of routing attacks. Moreover, the proposed routing algorithm defines an energy-efficient trust information exchange scheme that enables rapid trust knowledge building with low energy consumption. The performance of the proposed solution is thoroughly evaluated, using computer simulations for network topologies consisting of up to 1000 nodes.The gradient routing solution that is based on the IETF standardized RPL protocol is expected to be widely adopted within the next few years. We exploit the fact that IETF leaves open the definition of the routing metric that will be employed to guide the construction of Directed Acyclic Graphs to define a routing metric composition framework. Based on our framework, a system designer/user can select among a variety of primary routing metrics or define his/her own metrics that lead to the optimization of a specific network performance aspect (e.g. delay, throughput, energy). Moreover, the proposed framework clearly sets the necessary and sufficient conditions ensuring that the proper combination of selected metrics will ensure that the produced routing protocol will converge to optimal and loop free paths. We use the routing algebra to prove that once the primary routing metrics hold specific properties, the composite metric will also hold the necessary and sufficient properties for the routing protocol. In this perspective, we define trust and energy-related primary routing metrics that we prove to hold the abovementioned properties and, based on computer simulations, we prove that the proposed composite routing metrics can lead to a well-balanced performance in terms of the selected aspects. To ensure the feasibility of our approach which is a premium requirement, we have implemented both routing solutions in real-world state-of-the-art sensor nodes, named Iris and Telosb, respectively. The implementation results together with results from the protocol operation are reported and compared to computer simulations.Τα ασύρματα δίκτυα αισθητήρων (Wireless Sensor Networks-WSNs) εμφανιστήκαν πριν από περίπου δυο δεκαετίες και έκτοτε έχουν γνωρίσει τεράστια άνθιση. Τα πεδία εφαρμογών τους έχουν πολλαπλασιαστεί, καλύπτοντας μεγάλο εύρος εφαρμογών ξεκινώντας από περιβαλλοντικές έως στρατιωτικές εφαρμογές. Αυτή η εξάπλωση οφείλεται στα ιδιαίτερα πλεονεκτήματα που προσφέρουν, όπως το χαμηλό κόστος, η εύκολη εγκατάσταση, η ασύρματη επικοινωνία. Η δυναμική τους εξάπλωση έκανε τους σχεδιαστές του μελλοντικού Διαδικτύου να θεωρούν πλέον τα WSN ως μια πολύτιμη πηγή πληροφορίας πραγματικού χρόνου, η οποία αξιοποιούμενη θα μπορούσε να βελτιώσει το παρεχόμενο επίπεδο υπηρεσιών των χρηστών του Διαδικτύου στο μέλλον. Παρά την δημοτικότητά τους, τα δίκτυα αισθητήρων εμφανίζουν συγκεκριμένες ιδιαιτερότητες, οι οποίες απαιτείται να ληφθούν υπόψη. Οι κόμβοι που συνιστούν το δίκτυο χαρακτηρίζονται από περιορισμένους πόρους κυρίως σ’ ό,τι αφορά την επεξεργαστική ισχύ, τη μνήμη, την επικοινωνία αλλά κυρίως την ενέργεια, αφού κατά κανόνα τροφοδοτούνται από μπαταρίες. Επιπλέον, προκειμένου τα δίκτυα αυτού του είδους να υποστηρίζουν μοντέλα αυτοργάνωσης, η διαδικασία δρομολόγησης των δεδομένων βασίζεται στην συνεργασία των κόμβων μεταξύ τους, καθιστώντας τα ευάλωτα σε επιθέσεις. Αυτές οι ιδιαιτερότητες καθιστούν αναγκαίο το σχεδιασμό πρωτοκόλλων δρομολόγησης που πληρούν τις απαιτήσεις των συγκεκριμένων εφαρμογών, αφενός αντιμετωπίζοντας επιθέσεις κατά του πρωτοκόλλου δρομολόγησης μέσω της χρήσης καινοτόμων μοντέλων διαχείρισης εμπιστοσύνης και αφετέρου υιοθετώντας στρατηγικές αποδοτικής διαχείρισης της ενέργειας με στόχο την αύξηση της διάρκειας ζωής του δικτύου. Στην παρούσα διδακτορική διατριβή αντιμετωπίζονται τα προαναφερθέντα προβλήματα προτείνοντας καινοτόμες λύσεις, οι οποίες συνδυάζουν την πληροφορία δρομολόγησης με μοντέλα ανάπτυξης σχέσεων εμπιστοσύνης μεταξύ των κόμβων και αποδοτικής διαχείρισης της ενέργειας. Με στόχο την ικανοποίηση των απαιτήσεων των σύγχρονων WSN για υποστήριξη πολλών εφαρμογών με διαφορετικά επίπεδα παροχής ποιότητας υπηρεσίας, κινητικότητας κόμβων και υψηλής πυκνότητας δικτύων, παρουσιάζονται δύο προσεγγίσεις δρομολόγησης με έμφαση στη διαχείριση της ενέργειας και της πληροφορίας εμπιστοσύνης. Ο προτεινόμενος γεωγραφικός αλγόριθμος ασφαλούς δρομολόγησης (ATSR) βασίζεται στη δρομολόγηση δεδομένων με βάση τη γεωγραφική θέση των κόμβων, γεγονός που τον καθιστά κατάλληλο αφενός για εφαρμογές σε δίκτυα μεγάλης κλίμακας που συμπεριλαμβάνουν κινητούς κόμβους και αφετέρου ικανό να αντιμετωπίσει μια πληθώρα επιθέσεων σε επίπεδο δρομολόγησης. Επιπλέον, ο αλγόριθμος υλοποιεί ένα σχήμα ταχείας ανάπτυξης και διάχυσης της πληροφορίας εμπιστοσύνης εντός του δικτύου με χαμηλό ενεργειακό κόστος. Η απόδοση της προτεινόμενης λύσης έχει αξιολογηθεί μέσω εκτενών προσομοίωσαν σε Η/Υ σε τοπολογίες αποτελούμενες από μεγάλο πλήθος κόμβων. Η δεύτερη προσέγγιση δρομολόγησης βασίζεται στο τυποποιημένο από την IETF πρωτόκολλο RPL, το οποίο αναμένεται να τύχει ευρείας εφαρμογής τα επόμενα χρόνια. Το γεγονός ότι η IETF δίνει την δυνατότητα στο χρήστη να ορίσει την δική του μετρική με βάση την οποία θα δημιουργηθεί ο κατευθυνόμενος άκυκλος γράφος δρομολόγησης αποτελεί βασικό πλεονέκτημα του εν λόγω αλγορίθμου. Πλέον ο χρήστης βασιζόμενος στο προτεινόμενο σε αυτή τη διατριβή πλαίσιο έχει την δυνατότητα να επιλέξει ανάμεσα από μια ποικιλία βασικών μετρικών δρομολόγησης (primary routing metrics) ή ακόμα και να ορίσει μία δική του, με στόχο την βελτιστοποίηση μιας συγκεκριμένης πτυχής της απόδοσης του δικτύου. Επιπλέον, το παραπάνω πλαίσιο ορίζει όλες τις αναγκαίες και ικανές συνθήκες που πρέπει να ισχύουν και προτείνονται τρόποι σύνθεσης των βασικών μετρικών ώστε να διασφαλιστεί η δημιουργία (συνθετών) μετρικών δρομολόγησης που να οδηγούν σε πρωτόκολλο που συγκλίνει σε βέλτιστα μονοπάτια απαλλαγμένα από βρόγχους. Αποδεικνύεται, χρησιμοποιώντας την άλγεβρα δρομολόγησης, ότι εφόσον οι βασικές μετρικές δρομολόγησης πληρούν συγκεκριμένες ιδιότητες, τότε και οι σύνθετες μετρικές που θα προκύψουν θα πληρούν τις αναγκαίες και ικανές ιδιότητες για το πρωτόκολλο δρομολόγησης. Υπό αυτή την προοπτική ορίζονται βασικές μετρικές που αντιστοιχούν στην διαχείριση της εμπιστοσύνης και της ενέργειας στα WSN, αποδεικνύεται ότι πληρούν τις προαναφερθείσες ιδιότητες και μέσω προσομοιώσεων σε περιβάλλον Η/Υ δείξαμε ότι οι προτεινόμενες σύνθετες μετρικές μπορούν να οδηγήσουν σε βελτιωμένη απόδοση όσον αναφορά σε συγκεκριμένες πτυχές.Για να διασφαλιστεί ότι οι προτεινόμενες προσεγγίσεις είναι εφαρμόσιμες στο διαθέσιμο υλισμικό αισθητήρων έγινε υλοποίηση των δύο προτεινόμενων λύσεων δρομολόγησης σε πραγματικούς κόμβους (τύπου telosb/iris). Τα αποτελέσματα από την διαδικασία υλοποίησης καθώς και από την λειτουργία του δικτύου αξιολογήθηκαν και συγκριθήκαν με αυτά που προέκυψαν από τις προσομοιώσεις σε περιβάλλον Η/Υ

Comprehensive Comparison of VNE Solutions Based on Different Coordination Approaches

Virtualization is commonly accepted as the catalyst that would grant the internet the ability to shed the shackles of legacy technologies and evolve to its future self. In order to make this transformation feasible, unavoidable concurrent radical remodeling of all the involved counterparts is required, particularly in the context of automatically and optimally serving application requests by taking advantage of new virtualized environments and their latent capabilities. A considerable number of embedding strategies that efficiently map virtual computational and networking demands over physical resources have already been proposed in the literature, following different strategies. Among these suggested strategies, different coordination proposals have been adopted, in order to solve the node and link mapping functions. In this paper, we study the capabilities of the most popular embedding strategies, based on their coordination categorization. Our study confirms that by invoking a coordination strategy, especially the single stage one, added benefits on multiple performance layers can be achieved. Moreover, we propose a new mixed coordination algorithm, essentially creating a new category in the field of VNE coordination strategies

Advanced First Responders’ Services by Using FASTER Project Architectural Solution

Part 1: 6th Workshop on “5G – Putting Intelligence to the Network Edge” (5G-PINE 2021)International audienceAs the 5G technologies start to become a reality in telecommunication networks, more services and applications are designed to take advantage of the new features that 5G technology is offering. Additionally, several vertical sectors are using advanced applications in order to improve their performances. One important vertical is the Mission Critical Services (MCS) sector, which could significantly exploit 5G networks. When an emergency event occurs, such as a strong earthquake or a flood, the network traffic is proved to be rapidly increased. At the same time, the first responders need all the available resources in order to offer their services efficiently. In a situation like the one described which is extremely demanding and the available resources should be used as a priority by the first responders, the existing 4G network does not seem to be sufficient. It must be ensured that the first responders could be interconnected in a reliable network, which will provide a low latency and ultra-high throughput transmission being able to support all the advanced equipment and devices (UAVs, robots, AMRs, augmented reality and virtual reality glasses, etc.) that the first responders need. These requirements are satisfied by 5G networks. The 5G network architecture has been designed and implemented based on a new approach. The 5G network architecture that was designed and implemented for the needs of FASTER project and the advantages that this architecture offers to the first responders is presented in this paper

Comprehensive Comparison of VNE Solutions Based on Different Coordination Approaches

Virtualization is commonly accepted as the catalyst that would grant the internet the ability to shed the shackles of legacy technologies and evolve to its future self. In order to make this transformation feasible, unavoidable concurrent radical remodeling of all the involved counterparts is required, particularly in the context of automatically and optimally serving application requests by taking advantage of new virtualized environments and their latent capabilities. A considerable number of embedding strategies that efficiently map virtual computational and networking demands over physical resources have already been proposed in the literature, following different strategies. Among these suggested strategies, different coordination proposals have been adopted, in order to solve the node and link mapping functions. In this paper, we study the capabilities of the most popular embedding strategies, based on their coordination categorization. Our study confirms that by invoking a coordination strategy, especially the single stage one, added benefits on multiple performance layers can be achieved. Moreover, we propose a new mixed coordination algorithm, essentially creating a new category in the field of VNE coordination strategies

Optimal resource optimisation based on multi‐layer monitoring

Abstract The satisfaction of the Quality of Service (QoS) levels during an entire service life‐cycle is one of the key targets for Service Providers (SP). To achieve this in an optimal way, it is required to predict the exact amount of the needed physical and virtual resources, for example, CPU and memory usage, for any possible combination of parameters that affect the system workload, such as number of users, duration of each request, etc. To solve this problem, the authors introduce a novel architecture and its open‐source implementation that a) monitors and collects data from heterogeneous resources, b) uses them to train machine learning models and c) tailors them to each particular service type. The candidate solution is validated in two real‐life services showing very good accuracy in predicting the required resources for a large number of operational configurations where a data augmentation method is also applied to further decrease the estimation error up to 32%