Analysis and design of efficient techniques for video transmission in IEEE 802.11 wireless ad hoc networks

[EN] Wireless mobile ad ho networks, also known as MANETs, are omposed by independent mobile stations that ommuni ate without requiring any sort of infrastru ture for support. These networks are hara terized by variable bandwidth values and frequent path breaks, whi h are due to hannel noise, interferen e between stations and mobility. Su h fa tors require significant adaptation apabilites at different levels of the proto ol suites employed, enabling stations to qui kly respond to fast- hanging network onditions. Resear h on the most adequate proto- ols for the physi al, MAC and routing layers is still on-going, though some basi onsensus has already been rea hed and several testbeds have been setup around the world. To deploy real-time multimedia servi es, namely voi e and video, on top of su h an unreliable network environment is a very hallenging task. In this thesis we propose to a hieve that goal starting from urrently available Wi-Fi te hnology, and gradually finding the most adequate enhan ements to ea h proto ol layer of interest; we then ombine these enhan ements until we a hieve a omplete QoS framework for ad ho networks. By using urrently available te hnology we assure that the proposal of this thesis has an inherent high-level of appli ability on real life environments. Sin e our working field fo uses on video transmission over wireless ad ho networks, we will show how it is possible to support several QoS- onstrained video streams in MANET environments hara terized by moderate to high mobility levels, and by a significant amount of best efort traffic[ES] Las redes inalámbricas ad hoc, también conocidas como redes MANET, están compuestas por un conjunto de estaciones móviles independientes capaces de omunicarse entre sí sin necesidad de ningún tipo de infraestructura común de comunicaciones. Estas redes se caracterizan por tener un ancho de banda variable y pérdidas frecuentes de ruta que se pueden atribuir al ruido del anal inalámbrico, a la interferencia entre las estaciones móviles o bien a la movilidad de las estaciones. Dichos factores requieren una gran capacidad de adaptación en las diferentes capas de la arquitectura de protocolos, permitiendo a una estación responder rápidamente a posibles cambios bruscos en las condiciones de la red. A pesar de que aún se están realizando trabajos de investigación en bus a de los protocolos más adecuados para las capas físicas, a eso al medio (MAC) y encaminamiento, ha sido posible llegar a un nivel básico de consenso, lo cual ha permitido el despliegue de plataformas y entornos aplicados que utilizan tecnología de red MANET. Ofrecer servicios multimedia, como voz y vídeo, en redes con tan poca habilidad es un desafío importante. En esta tesis nos proponemos alcanzar este objetivo partiendo de la tecnología Wi-Fi actualmente disponible, encontrando de forma paulatina las mejoras más importantes en las diferentes capas de la arquitectura de red, para llegar, finalmente, a una solución integrada capaz de ofrecer calidad de servicio (QoS) en las redes MANET. Al utilizar la tecnología que disponemos actualmente nos aseguramos que las propuestas de esta tesis tengan un alto grado de aplicabilidad en entornos reales. Ya que la línea de trabajo de la tesis está aplicada a la transmisión de vídeo en redes MANET, demostraremos que es posible ofrecer calidad de servicio a varios flujos de vídeo en una red MANET caracterizada por altos grados de movilidad en sus nodos y un nivel significativo de tráfico o de tipo best effortTavares De Araujo Cesariny Calafate, CM. (2006). Analysis and design of efficient techniques for video transmission in IEEE 802.11 wireless ad hoc networks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/135282TESI

On the Use of Mobile Sensors for Estimating City-Wide Pollution Levels

©2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Obtaining detailed pollution maps for urban environments is an effort that is gathering much interest by allowing to better regulate traffic and protect citizens from hazardous conditions. However, the scarcity of pollution sensors prevents obtaining the desired degree of detail, requiring alternative solutions to be deployed. In this paper we explore the concept of mobile pollution sensing by studying the feasibility of equipping buses with ozone measurement hardware to estimate ozone patterns for the city of Compiègne. Overall, we achieve accurate estimations, with error values typically ranging from 2% to 10%. Compared to solutions based on deploying static sensors on the different bus stops available, we find that the proposed mobile sensing approach is able to provide a degree of accuracy comparable to deploying tens of static sensors, substantially reducing costs and management.This work was carried out and funded in the framework of the Labex MSZT. It was supported by the French Government, through the program "Investments for the future” managed by the National Agency for Research (Reference ANR-11-IDEX-0004-02). This work was partially funded by the Celtic Plus CoMoSeF project "Cooperative mobility for the services of the future". The authors thank the Agglomération de la Région de Compiégne (ARC).Tavares De Araujo Cesariny Calafate, CM.; Ducourthial, B. (2015). On the Use of Mobile Sensors for Estimating City-Wide Pollution Levels. IEEE. doi:10.1109/IWCMC.2015.7289093

Unmanned Aerial Vehicles-Platforms, Applications, Security and Services

Tavares De Araujo Cesariny Calafate, CM.; Tropea, M. (2020). Unmanned Aerial Vehicles-Platforms, Applications, Security and Services. Electronics. 9(6):1-3. https://doi.org/10.3390/electronics9060975S1396Stellin, M., Sabino, S., & Grilo, A. (2020). LoRaWAN Networking in Mobile Scenarios Using a WiFi Mesh of UAV Gateways. Electronics, 9(4), 630. doi:10.3390/electronics9040630Hiba, A., Sántha, L. M., Zsedrovits, T., Hajder, L., & Zarandy, A. (2020). Onboard Visual Horizon Detection for Unmanned Aerial Systems with Programmable Logic. Electronics, 9(4), 614. doi:10.3390/electronics9040614Tropea, M., Fazio, P., De Rango, F., & Cordeschi, N. (2020). A New FANET Simulator for Managing Drone Networks and Providing Dynamic Connectivity. Electronics, 9(4), 543. doi:10.3390/electronics9040543Chen, C.-L., Deng, Y.-Y., Weng, W., Chen, C.-H., Chiu, Y.-J., & Wu, C.-M. (2020). A Traceable and Privacy-Preserving Authentication for UAV Communication Control System. Electronics, 9(1), 62. doi:10.3390/electronics9010062Khan, M. A., Qureshi, I. M., Ullah, I., Khan, S., Khanzada, F., & Noor, F. (2019). An Efficient and Provably Secure Certificateless Blind Signature Scheme for Flying Ad-Hoc Network Based on Multi-Access Edge Computing. Electronics, 9(1), 30. doi:10.3390/electronics9010030Wubben, J., Fabra, F., Calafate, C. T., Krzeszowski, T., Marquez-Barja, J. M., Cano, J.-C., & Manzoni, P. (2019). Accurate Landing of Unmanned Aerial Vehicles Using Ground Pattern Recognition. Electronics, 8(12), 1532. doi:10.3390/electronics8121532Zhou, Y., Wu, C., Wu, Q., Eli, Z. M., Xiong, N., & Zhang, S. (2019). Design and Analysis of Refined Inspection of Field Conditions of Oilfield Pumping Wells Based on Rotorcraft UAV Technology. Electronics, 8(12), 1504. doi:10.3390/electronics812150

Breaking persistent working group partnerships: a social experiment

Facing multidisciplinary projects is becoming quite common in companies worldwide, meaning that experts from a specific area must team up with experts from other areas in a dynamic, ad hoc manner. For a professional to meet such requirements successfully, it is important that teamwork skills are developed during college. However, such issue is usually not addressed thoroughly, and most students end up teaming with the same partners over and over again, thereby failing to achieve the critical adaptability skills expected from them. To address this drawback, in this paper we present the results of a study where students were forced to team up with other partners based on the results of a computer networking skills-ranking exam. Experimental results confirm the repeating pattern in terms of past partnerships, and student resistance to partner changes. On the positive side, results show that having new partners indeed help at achieving a more even task distribution, and that students are moderately aware of the upcoming challenges in their future professional activity, recognizing the benefits of teaming up with new people.This work was partially supported by the School of Informatics (ETSINF) and the Department of Computer Engineering (DISCA) at the Universitat Politècnica de València.Tavares De Araujo Cesariny Calafate, CM.; Arlandis, J.; Torres Cortes, A. (2015). Breaking persistent working group partnerships: a social experiment. En INTED2015 Proceedings. IATED. 1329-1337. http://hdl.handle.net/10251/70447S1329133

Detection of glaucoma using three-stage training with EfficientNet

[EN] This paper sets forth a methodology that is based on three-stage-training of a state-of-the-art network architecture previously trained on Imagenet, and iteratively finetuned in three steps; freezing first all layers, then re-training a specific number of them and finally training all the architecture from scratch, to achieve a system with high accuracy and reliability. To determine the performance of our technique a dataset consisting of 17.070 color cropped samples of fundus images, and that includes two classes, normal and abnormal, is used. Extensive evaluations using baselines models (VGG16, InceptionV3 and Resnet50) are carried out, in addition to thorough experimentation with the proposed pipeline using variants of EfficientNet and EfficientNetV2. The training procedure is described accurately, putting emphasis on the number of parameters trained, the confusion matrices (with analysis of false positives and false negatives), accuracy, and F1-score obtained at each stage of the proposed methodology. The results achieved show that the intelligent system presented for the task at hand is reliable, presents high precision, its predictions are consistent and the number of parameters needed to train are low compared to other alternatives.This work is supported by the HK Innovation and Technology Commission (InnoHK Project CIMDA), the HK Research Grants Council (Project CityU 11204821) and City University of Hong Kong (Project 9610034). We acknowledge the support of Universitat Politècnica de València; R&D project PID2021-122580NB-I00, funded by MCIN/AEI/ 10.13039/501100011033 and ERDF.De Zarzà, I.; De Curtò, J.; Tavares De Araujo Cesariny Calafate, CM. (2022). Detection of glaucoma using three-stage training with EfficientNet. Intelligent Systems with Applications. 16:1-10. https://doi.org/10.1016/j.iswa.2022.2001401101

A comparative study of two automated workgroup composition strategies

[EN] Nowadays, the professional environment of leading companies requires multidisciplinary teams to be created, including both internal and external experts, to adequately face the challenges of a fast-evolving and complex market. For newcomers, this situation can be difficult to handle if no previous experiences allowed preparing them for those situations. This is where college education finds its place, and in fact the curricula of different university careers are being updated to include more transversal competences like leadership and cooperation skills within groups. However, such efforts still remain at an amateur level in most cases due to lack of specific expertise by the majority of instructors, due to limitations in terms of creating actual multidisciplinary groups, and due to the little resources available to maximize the benefits of such experiences. Students also show little involvement in this issue, typically opting for approaches that minimize their efforts. Thus, simple and yet effective strategies that can be helpful for instructors to make a meaningful change to the current status quo are necessary. To address this need, in this paper we present the results of a 2-year study where students were forced to team up with other partners based on the results of a computer networking skills-ranking exam. In the first experiment, groups where formed by students achieving a similar performance (homogeneous), while in the second experiment groups were formed so that the average score of group members was the same (mostly heterogeneous). Through detailed survey results taken by students at the end of both courses, we find that, compared to an alternative group assignment strategy promoting group heterogeneity, having partners with similar skills does not help at improving the coordination between group members nor students perception about the usefulness of the experience towards future jobs. In fact, their rating of the overall experience was mostly the same, and, to our surprise, the partner expertise on the course topics was not a motivating factor, being that students complaints were always about not being able to decide about their partner. Thus, we consider that a simple strategy to define groups (e.g. randomly) suffices, but it should be adopted on all courses since the first year of the degree.Tavares De Araujo Cesariny Calafate, CM.; Tornell, SM.; Arlandis, J. (2016). A comparative study of two automated workgroup composition strategies. En INTED2016 Proceedings. IATED Digital Library. 5890-5899. doi:10.21125/inted.2016.0409S5890589

Supporting Beacon and Event-Driven Messages in Vehicular Platoons through Token-Based Strategies

[EN] Timely and reliable inter-vehicle communications is a critical requirement to support traffic safety applications, such as vehicle platooning. Furthermore, low-delay communications allow the platoon to react quickly to unexpected events. In this scope, having a predictable and highly effective medium access control (MAC) method is of utmost importance. However, the currently available IEEE 802.11p technology is unable to adequately address these challenges. In this paper, we propose a MAC method especially adapted to platoons, able to transmit beacons within the required time constraints, but with a higher reliability level than IEEE 802.11p, while concurrently enabling efficient dissemination of event-driven messages. The protocol circulates the token within the platoon not in a round-robin fashion, but based on beacon data age, i.e., the time that has passed since the previous collection of status information, thereby automatically offering repeated beacon transmission opportunities for increased reliability. In addition, we propose three different methods for supporting event-driven messages co-existing with beacons. Analysis and simulation results in single and multi-hop scenarios showed that, by providing non-competitive channel access and frequent retransmission opportunities, our protocol can offer beacon delivery within one beacon generation interval while fulfilling the requirements on low-delay dissemination of event-driven messages for traffic safety applications.This work was partially supported by the Knowledge Foundation (KKS) via the ELECTRA project, the SafeCOP project, which is funded from the ECSEL Joint Undertaking under grant agreement n0 692529, and from national funding.Balador, A.; Uhlemann, E.; Tavares De Araujo Cesariny Calafate, CM.; Cano, J. (2018). Supporting Beacon and Event-Driven Messages in Vehicular Platoons through Token-Based Strategies. Sensors. 18(4):1-17. https://doi.org/10.3390/s18040955S117184Omar, H. A., Zhuang, W., & Li, L. (2013). VeMAC: A TDMA-Based MAC Protocol for Reliable Broadcast in VANETs. IEEE Transactions on Mobile Computing, 12(9), 1724-1736. doi:10.1109/tmc.2012.142Bergenhem, C., Hedin, E., & Skarin, D. (2012). Vehicle-to-Vehicle Communication for a Platooning System. Procedia - Social and Behavioral Sciences, 48, 1222-1233. doi:10.1016/j.sbspro.2012.06.1098Hadded, M., Muhlethaler, P., Laouiti, A., Zagrouba, R., & Saidane, L. A. (2015). TDMA-Based MAC Protocols for Vehicular Ad Hoc Networks: A Survey, Qualitative Analysis, and Open Research Issues. IEEE Communications Surveys & Tutorials, 17(4), 2461-2492. doi:10.1109/comst.2015.2440374Fernandes, P., & Nunes, U. (2012). Platooning With IVC-Enabled Autonomous Vehicles: Strategies to Mitigate Communication Delays, Improve Safety and Traffic Flow. IEEE Transactions on Intelligent Transportation Systems, 13(1), 91-106. doi:10.1109/tits.2011.2179936Hassanabadi, B., & Valaee, S. (2014). Reliable Periodic Safety Message Broadcasting in VANETs Using Network Coding. IEEE Transactions on Wireless Communications, 13(3), 1284-1297. doi:10.1109/twc.2014.010214.122008OMNeT++http://www.omnetpp.orgSommer, C., German, R., & Dressler, F. (2011). Bidirectionally Coupled Network and Road Traffic Simulation for Improved IVC Analysis. IEEE Transactions on Mobile Computing, 10(1), 3-15. doi:10.1109/tmc.2010.133Akhtar, N., Ergen, S. C., & Ozkasap, O. (2015). Vehicle Mobility and Communication Channel Models for Realistic and Efficient Highway VANET Simulation. IEEE Transactions on Vehicular Technology, 64(1), 248-262. doi:10.1109/tvt.2014.231910

A density-based contention window control scheme for unicast communications in vehicular ad hoc networks

[EN] Achieving a well-designed medium access control (MAC) protocol is a challenging issue to improve communications efficiency due to the dynamic nature of vehicular ad hoc networks (VANETs). IEEE 802.11p standard was selected as the best choice for vehicular environments considering its availability, maturity, and cost. The common problem in all IEEE 802.11 based protocols is scalability, exhibiting performance degradation in highly variable network scenarios. Experimental results for the IEEE 802.11-based MAC protocol show the importance of contention window adjustment on communications performance; However the vehicular communications community has not yet addressed this issue in unicast communication environments. This paper proposes a novel contention window control scheme for VANET environments based on estimating the network density, which is then used to dynamically adapt the CW size. Analysis and simulation results showthat our proposal provides better overall performance compared with previous proposals, even in high network density scenarios.This work was supported by the Ministerio de Economía y Competitividad, Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad, Proyectos I+D+I 2014, Spain, under Grant TEC2014-52690-R.Balador, A.; Tavares De Araujo Cesariny Calafate, CM.; Cano, J.; Manzoni, P. (2017). A density-based contention window control scheme for unicast communications in vehicular ad hoc networks. International Journal of Ad Hoc and Ubiquitous Computing. 24(1-2):65-75. doi:10.1504/IJAHUC.2017.080913S6575241-

On the Correlation Between Heart Rate and Driving Style in Real Driving Scenarios

[EN] Driving safety is of utmost importance in our society. The number of fatalities due to car accidents is still very high, and reducing this trend requires as much attention as possible. There are situations where the emotional conditions of drivers vary due to reasons beyond their control, or because they decide to change their driving style. Hence, we consider that such frequent situations deserve more scrutiny. In this work we addressed such issues by designing an Android application able to monitor in real-time both physiological data from the driver and diagnostic data from the vehicle (this data is obtained using an OBD-II connector) to study their correlation. Among the various non-invasive biomedical sensors available nowadays, we have adopted heart rate sensors, either packaged in belts or in smart watches. This allows studying the relationship between driving aggressiveness and heart rate. For our analysis we focused on fourteen different routes accounting a total driving time of 6 hours and 2 minutes, which we have split into three separate categories: urban, suburban, and highway routes. We analyzed the correlation between the heart rate and the driving style for each of the three groups. Our experiments show that the differences in terms of heart rate between quiet and aggressive behavior range between 2.5 % and 3 % beats per minute higher for the latter behaviour compared to the former.This work was partially supported by the Ministerio de Economia y Competitividad, Programa Estatal de Investigacion, Desarrollo e Innovacion Orientada a los Retos de la Sociedad, Proyectos I+D+I 2014, Spain, under Grant TEC2014-52690-R.Meseguer Anastasio, JE.; Tavares De Araujo Cesariny Calafate, CM.; Cano, J. (2017). On the Correlation Between Heart Rate and Driving Style in Real Driving Scenarios. Mobile Networks and Applications. 1-8. doi:10.1007/s11036-017-0833-xS18Gibson PM, Wiesenthal DL (1996) The Driving Vengeance Questionnaire (DVQ): the development of a scale to measure deviant drivers, LaMarsh Research Programme Report Series, No. 54Cohen S (1980) After effects of stress on human performance and social behavior: a review of research and theory. Psychol Bull 88:82–108Gravina R, Fortino G (2016) Automatic Methods for the Detection of Accelerative Cardiac Defense Response. IEEE Trans Affect Comput 7(3):Andreoli A et al SPINE-HRV: A BSN-based toolkit for heart rate variability analysis in the time-domain, Wearable and Autonomous Systems, pp 369–389Karel A, Cornelie JG, Tineke H (2001) Driving with a congestion assistant; mental workload and acceptance. Psychophysiol Ergon 40(6):1019–1025Shuii S, Kazushi T, Masanori K (2001) Heart rate variability during long truck driving work. J Human Ergol 30(1-2):235–240Keyword Protocol 2000 (1999) International Organization for StandardizationISO 9141-2:1994/Amd 1:1996,1196 (1996) International Organization for StandardizationKhan MA, Raza A (2013) Development of an On-board Diagnostic (OBD) Kit for Troubleshooting of Compliant Vehicle, Emerging Technologies (ICET), 2013 IEEE 9th International ConferenceHaykin S (1994) Neural Networks: A Comprehen-sive Foundation, Macmillan, p 2Hecht-Nielsen R (1989) Theory of the backpropagation neural network - Neural Networks, IJCNN., International Joint ConferenceMeseguer J.E, Calafate C.T, Cano JC, Manzoni P (2015) Assessing the Impact of Driving Behavior on Instantaneous Fuel Consumption, IEEE 12th Consumer Communications and Networking ConferenceKuhler M, Kartens D (1978) Improved driving cycle for testing automotive exhaust emissions, SAE Technical Paper Series 780650Johansson H et al (2003) Impact of EcoDriving on emissions. International Scientific Symposium on Transport and Air Pollution, Avignon, FranceRakha H (2011) Simple Comprehensive Fuel Consumption and CO2 Emission Model based on Instantaneous Vehicle Power. Transportation Research Board Annual Meeting, Washington, D.C.Meseguer JE, Calafate CT, Cano JC, Manzoni P (2013) DrivingStyles: a smartphone application to assess driver behavior, 18th IEEE symposium on Computers and CommunicationsRiener A (2012) Subliminal Persuasion and Its Potential for Driver Behavior Adaptation, IEEE Transactions On Intelligent Transportation, pp 1–10ELM327DS (2010) OBD to RS232 Interpreter, Elm Electronics CircuitsLajunen T, Parker D, Summala H (1999) Does traffic congestion increase driver aggression?, Transportation Research Part F2 225-23

Epidgeons: Combining Drones and DTNs Technologies to Provide Connectivity in Remote Areas

© Owner/Author. 2015 This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in ACM, In Proceedings of the First Workshop on Micro Aerial Vehicle Networks, Systems, and Applications for Civilian Use (pp. 57-58). http://dx.doi.org/10.1145/2750675.2750688.In certain geographical areas such as the rural areas or the developing regions, the lack of infrastructure, the temporary nature of the connections and the limited access to fixed public networks does not allow the use of all the advantages offered by the Internet. In this paper we present our project that aims to test a new communication system based on the combination of the use of unmanned aerial vehicles (called ePidgeons) and wireless networking technologies for Disruption Tolerant Networks (DTN). As a study case we will use the riparian communities along the rivers in the Amazon region.Manzoni, P.; Tavares De Araujo Cesariny Calafate, CM.; Cano Escribá, JC.; Mota, E. (2015). Epidgeons: Combining Drones and DTNs Technologies to Provide Connectivity in Remote Areas. ACM Digital Library. doi:10.1145/2750675.2750688SJ. Crowcroft, E. Yoneki, P. Hui, and T. Henderson, "Promoting tolerance for delay tolerant network research", ACM SIGCOMM Computer Communication Review, vol. 38, no. 5, Oct. 2008, pp. 63--68.Project "Networking for Communications Challenged Communities: Architecture, Test Beds and Innovative Alliances" (N4C), http://www.n4c.eu/.Project "DakNet", http://www.unitedvillages.com/.Phuong Tran Thi Ha, H. Yamamoto, K. Yamazaki, "Using Autonomous Air Vehicle in DTN Sensor Network for Environmental Observation", IEEE 37th Annual Computer Software and Applications Conference (COMPSAC) 2013, pp. 447--450.Uchida, N.; Kawamura, N.; Ishida, T.; Shibata, Y., "Proposal of Autonomous Flight Wireless Nodes with Delay Tolerant Networks for Disaster Use," 2014 Eighth International Conference on Innovative Mobile and Internet Services in Ubiquitous Computing (IMIS), 2-4 July 2014M. Coutinho, T. Moreira, E. Silva, A. Efrat, and T. Johnson. A new proposal of data mule network focused on Amazon riverine population. In Proceedings of the 3rd Extreme Conference on Communication: The Amazon Expedition (ExtremeCom '11). ACM, New York, NY, USAHervé Ntareme, Marco Zennaro, and Björn Pehrson. Delay tolerant network on smartphones: applications for communication challenged areas. In Proceedings of the 3rd Extreme Conference on Communication: The Amazon Expedition (ExtremeCom '11). ACM, New York, NY, USAMartinez-Vidal, Ruben, et al. "Mobile-agent based delay-tolerant network architecture for non-critical aeronautical data communications." Distributed Computing and Artificial Intelligence. Springer International Publishing, 2013. 513--520