14 research outputs found
Investigating secondary students' stance on IoT driven educational activities - Dataset
No full text<p>This data set supports the research and the results that are presented in Glaroudis, D., Iossifides, A., Spyropoulou, N., Zaharakis, I. D., “Investigating Secondary Students' Stance on IoT Driven Educational Activities”. In Kameas A, and Stathis K. (Eds) Ambient Intelligence, LNCS 11249, 2018, pp. 188-203. Springer Nature Switzerland AG. DOI: https://doi.org/10.1007/978-3-030-03062-9_15.</p>
A successive coordinated power allocation water-filling algorithm for heterogeneous OFDMA cellular systems
No full text
A Robust OFDM IM-QAM NOMA Scheme for URLLC and eMBB Downlink Service Coexistence
No full textThis work introduces a non-orthogonal multiple access (NOMA) downlink scheme, reinforced by a simple multiplexing technique of index modulation (IM) and quadrature amplitude modulation (QAM) signals, tailored to minimize their mutual interference. Integrated with orthogonal frequency division multiplexing (OFDM), this scheme achieves low bit error probability for the IM signal, at the cost of lower information rate, while practically affecting the performance of the QAM signal only due to power sharing. These characteristics, along with the provided wide range of power allocation possibilities, facilitate favorable user pairing strategies, which can be efficiently applied to multiplexing low-rate ultra-reliable low-latency communication (URLLC) and enhanced mobile broadband (eMBB) services, conveyed by the IM, and QAM signals, respectively. Aiming at providing a proof of concept of the proposed scheme, the bit error probability of both signals, the rate reduction of the eMBB service under a power constraint, and the excess power required for the URLLC service, on top of the eMBB service, are quantified and analyzed, over diversity Rayleigh fading channels, with conventional, low complexity detection. Overall, the results show that the proposed scheme provides a robust solution for URLLC and eMBB downlink service coexistence for 5G communications and beyond
A Survey of Strategies for Communication Networks to Protect Against Large-Scale Natural Disasters
No full textRecent natural disasters have revealed that emergency networks presently cannot disseminate the necessary disaster information, making it difficult to deploy and coordinate relief operations. These disasters have reinforced the knowledge that telecommunication networks constitute a critical infrastructure of our society, and the urgency in establishing protection mechanisms against disaster-based disruptions. Hence, it is important to have emergency networks able to maintain sustainable communication in disaster areas. Moreover, the network architecture should be designed so that network connectivity is maintained among nodes outside of the impacted area, while ensuring that services for costumers not in the affected area suffer minimal impact. As a first step towards achieving disaster resilience, the RECODIS project was formed, and its Working Group 1 members conducted a comprehensive literature survey on "strategies for communication networks to protect against large-scale natural disasters," which is summarized in this article
An approach to advance STEM education practices based on IoT technologies and the CoPs paradigm
No full textInternet of Things and other state-of-the-art technologies like mobile and ubiquitous computing present ample opportunities for developing novel so- lutions almost in every domain of modern life. The research work presented here aims to leverage on the potential of such technologies in the direction of enhancing learning practices in secondary level education and promoting posi- tive attitudes towards the corresponding scientific and engineering disciplines. The originality of the proposed approach lies on the provision of an educational platform, framed by contemporary pedagogical principles, and with an aim to stimulate collaboration between the relevant stakeholders in the form of opera- tional communities of practice. Such communities are brought together on the basis of participating in on line activities, problem solving, exchanging reflec- tions and experiences in the context of educational scenarios that incorporate modern technologies. The platform development is discussed in terms of the underlined conceptual models, the defined stakeholders’ requirements, the on- line services developed, the software tools integrated and the data management supported. An example educational scenario, the corresponding IoT application developed and preliminary evaluation results of this approach are also reported.The final authenticated version is available online at https://doi.org/10.1007/978-3-030-21151-6_
A survey of strategies for communication networks to protect against large-scale natural disasters
No full textRecent natural disasters have revealed that emergency networks presently cannot disseminate the necessary disaster information, making it difficult to deploy and coordinate relief operations. These disasters have reinforced the knowledge that telecommunication networks constitute a critical infrastructure of our society, and the urgency in establishing protection mechanisms against disaster-based disruptions. Hence, it is important to have emergency networks able to maintain sustainable communication in disaster areas. Moreover, the network architecture should be designed so that network connectivity is maintained among nodes outside of the impacted area, while ensuring that services for costumers not in the affected area suffer minimal impact. As a first step towards achieving disaster resilience, the RECODIS project was formed, and its Working Group 1 members conducted a comprehensive literature survey on “strategies for communication networks to protect against large-scale natural disasters,” which is summarized in this article.Network Architectures and Service
Investigating Inclusiveness and Backward Compatibility of IEEE 802.11be Multi-link Operation
No full textNowadays is not possible to avoid considering the coexistence and the fusion of different wireless technologies
as completely separated entities. The ever-growing number of devices employing multi-RATs (Radio Access Technologies) that require continuous wireless connectivity is posing great challenges. Furthermore, the requirements in terms of both throughput and latency originated by the use cases, are pushing the current technologies to their limits, especially for indoor dense deployments that are usually covered by Wi-Fi. The IEEE 802.11 Working Group is currently tackling such challenges by working on a new amendment of the standard (namely 802.11be), which introduces, among other novelties, the multi-link operation (MLO). Through MLO, the target is to achieve simultaneous transmission over multiple bands to obtain massive bitrate up
to 40 Gbps. The introduction of MLO poses challenges on the coexistence with older legacy devices in mixed networks. This contribution explores how the coexistence of legacy IEEE 802.11 devices and new IEEE 802.11be devices realizing the proposed multi-link feature can be improved by using an appropriate static
band assignment policy. Another issue is how the overall network behaves when varying the number of devices and the legacy/new nodes ratio. Simulations for three different band allocation cases close to reality are developed. Performance results in terms of aggregated, average throughput and fairness are derived for
different conditions.This work has received funding from the European Union
(EU) Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie ETN TeamUp5G, grant
agreement No. 813391. This work was also supported by
Intelligence-Enabling Radio Communications for Seamless
Inclusive Interactions (INTERACT) through COST Action
under Grant CA20120, FCT/MCTES UIDB/50008/2020 and
SNF Scientific Exchange-AISpectrum (project 205842).info:eu-repo/semantics/acceptedVersio
STEM Learning and Career Orientation via IoT Hands-on Activities in Secondary Education
No full textThis work studies the influence of IoT-driven educational activities and tools (software, hardware and educational material) in STEM education as well as their role as STEM related career enablers to young boys and girls. The study builds on previous related results and applies to over 60 young students that are involved in hands-on learning activities in the context of a summer school. The analysis is based on especially designed close-ended and open-ended questionnaires as well as in-class observations and focuses on age and gender aspects. The results confirm the overall positive stance of the students on the educational activities and show that the provided tools under consideration are well accepted and effectively used. Furthermore, students’ choices regarding prospective future careers reveal that their views on STEM fields and related professions have significantly been enriched through their participation in the summer school.The final authenticated version is available online at https://doi.org/10.1109/PERCOMW.2019.873075
