GRCBox: Extending Smartphone Connectivity in Vehicular Networks

The low penetration of connectivity-enabled OBUs is delaying the deployment of Vehicular Networks (VNs), and therefore the development of Vehicular Delay Tolerant Network (VDTN) applications, among others. In this paper we present GRCBox, an architecture based on RaspberryPi that allows integrating smartphones in VNs. GRCBox is based on a low-cost device that combines several pieces of software to provide ad-hoc and multi-interface connectivity to smartphones. Using GRCBox each application can choose the interface for its data flows, which increases flexibility and will allow developers to easily implement applications based on ad-hoc connectivity, such as VDTN applications.This work was partially supported by the Ministerio de Economia y Competitividad, Spain, under Grants TIN2011-27543-C03-01 and BES-2012-052673, and by the European Commission under Svagata.eu, the Erasmus Mundus Programme, Action 2 (EMA2).Martínez Tornell, S.; Patra, S.; Tavares De Araujo Cesariny Calafate, CM.; Cano Escribá, JC.; Manzoni, P. (2015). GRCBox: Extending Smartphone Connectivity in Vehicular Networks. International Journal of Distributed Sensor Networks. 2015:1-13. doi:10.1155/2015/478064S1132015Hartenstein, H., & Laberteaux, K. P. (2008). A tutorial survey on vehicular ad hoc networks. IEEE Communications Magazine, 46(6), 164-171. doi:10.1109/mcom.2008.4539481Wu, H., Palekar, M., Fujimoto, R., Guensler, R., Hunter, M., Lee, J., & Ko, J. (2005). An empirical study of short range communications for vehicles. Proceedings of the 2nd ACM international workshop on Vehicular ad hoc networks - VANET ’05. doi:10.1145/1080754.1080769Jerbi, M., Senouci, S.-M., & Haj, M. A. (2007). Extensive Experimental Characterization of Communications in Vehicular Ad Hoc Networks within Different Environments. 2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring. doi:10.1109/vetecs.2007.533Lee, K. C., Lee, S., Cheung, R., Lee, U., & Gerla, M. (2007). First Experience with CarTorrent in a Real Vehicular Ad Hoc Network Testbed. 2007 Mobile Networking for Vehicular Environments. doi:10.1109/move.2007.4300814Giordano, E., Tomatis, A., Ghosh, A., Pau, G., & Gerla, M. (2008). C-VeT An Open Research Platform for VANETs: Evaluation of Peer to Peer Applications in Vehicular Networks. 2008 IEEE 68th Vehicular Technology Conference. doi:10.1109/vetecf.2008.462Cesana, M., Fratta, L., Gerla, M., Giordano, E., & Pau, G. (2010). C-VeT the UCLA campus vehicular testbed: Integration of VANET and Mesh networks. 2010 European Wireless Conference (EW). doi:10.1109/ew.2010.5483535Santa, J., Tsukada, M., Ernst, T., & Gomez-Skarmeta, A. F. (2009). Experimental analysis of multi-hop routing in vehicular ad-hoc networks. 2009 5th International Conference on Testbeds and Research Infrastructures for the Development of Networks & Communities and Workshops. doi:10.1109/tridentcom.2009.4976248Paula, M. C. G., Isento, J. N., Dias, J. A., & Rodrigues, J. J. P. C. (2011). A real-world VDTN testbed for advanced vehicular services and applications. 2011 IEEE 16th International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD). doi:10.1109/camad.2011.5941108Campbell, A., & Choudhury, T. (2012). From Smart to Cognitive Phones. IEEE Pervasive Computing, 11(3), 7-11. doi:10.1109/mprv.2012.41Vandenberghe, W., Moerman, I., & Demeester, P. (2011). On the feasibility of utilizing smartphones for vehicular ad hoc networking. 2011 11th International Conference on ITS Telecommunications. doi:10.1109/itst.2011.6060061Sawada, D., Sato, M., Uehara, K., & Murai, J. (2011). iDANS: A platform for disseminating information on a VANET consisting of smartphone nodes. 2011 11th International Conference on ITS Telecommunications. doi:10.1109/itst.2011.6060062Tornell, S. M., Calafate, C. T., Cano, J.-C., Manzoni, P., Fogue, M., & Martinez, F. J. (2013). Evaluating the Feasibility of Using Smartphones for ITS Safety Applications. 2013 IEEE 77th Vehicular Technology Conference (VTC Spring). doi:10.1109/vtcspring.2013.6692553Mitchell, G. (2012). The Raspberry Pi single-board computer will revolutionise computer science teaching. Engineering & Technology, 7(3), 26-26. doi:10.1049/et.2012.0300Fielding R. T.Architectural styles and the design of network-based software architectures [Ph.D. thesis]2000University of Californi

Neuronal lysosomal dysfunction releases exosomes harboring APP C-terminal fragments and unique lipid signatures

Defects in endolysosomal and autophagic functions are increasingly viewed as key pathological features of neurodegenerative disorders. A master regulator of these functions is phosphatidylinositol-3-phosphate (PI3P), a phospholipid synthesized primarily by class III PI 3-kinase Vps34. Here we report that disruption of neuronal Vps34 function in vitro and in vivo impairs autophagy, lysosomal degradation as well as lipid metabolism, causing endolysosomal membrane damage. PI3P deficiency also promotes secretion of unique exosomes enriched for undigested lysosomal substrates, including amyloid precursor protein C-terminal fragments (APP-CTFs), specific sphingolipids, and the phospholipid bis(monoacylglycero)phosphate (BMP), which normally resides in the internal vesicles of endolysosomes. Secretion of these exosomes requires neutral sphingomyelinase 2 and sphingolipid synthesis. Our results reveal a homeostatic response counteracting lysosomal dysfunction via secretion of atypical exosomes eliminating lysosomal waste and define exosomal APP-CTFs and BMP as candidate biomarkers for endolysosomal dysfunction associated with neurodegenerative disorders.Fan Wang for the kind gift of the Pi3kc3flox/flox mice. We thank Basant Abdulrahman and Hermann Schaetzl for providing the gene-edited Atg5 KO N2a cells. We are also grateful to Zhenyu Yue, Ralph Nixon, and Jean Gruenberg for the kind gift of anti-Atg14L, Cathepsin D, and BMP antibodies, respectively. We thank Thomas Südhof for sharing Cre recombinase lentiviruses. We thank the OCS Microscopy Core of New York University Langone Medical Center for the support of the EM work and Rocio Perez-Gonzalez and Efrat Levy of New York University for their support during optimization of the brain exosome isolation technique. We thank Elizabeta Micevska for the maintenance and genotyping of the animal colony and Bowen Zhou for the preliminary lipidomic analysis of conditional Pi3kc3 cKO mice. We also thank Rebecca Williams and Catherine Marquer for critically reading the manuscript. This work was supported by grants from the Fundação para a Ciência e Tecnologia (PD/BD/105915/2014 to A.M.M.); the National Institute of Health (R01 NS056049 to G.D.P., transferred to Ron Liem, Columbia University; T32-MH015174 to Rene Hen (Z.M.L.)). Z.M.L. and R.B.C. received pilot grants from ADRC grant P50 AG008702 to S.A.S.info:eu-repo/semantics/publishedVersio

Flying ad-hoc network application scenarios and mobility models

[EN] Flying ad-hoc networks are becoming a promising solution for different application scenarios involving unmanned aerial vehicles, like urban surveillance or search and rescue missions. However, such networks present various and very specific communication issues. As a consequence, there are several research studies focused on analyzing their performance via simulation. Correctly modeling mobility is crucial in this context and although many mobility models are already available to reproduce the behavior of mobile nodes in an ad-hoc network, most of these models cannot be used to reliably simulate the motion of unmanned aerial vehicles. In this article, we list the existing mobility models and provide guidance to understand whether they could be actually adopted depending on the specific flying ad-hoc network application scenarios, while discussing their advantages and disadvantages.Bujari, A.; Tavares De Araujo Cesariny Calafate, CM.; Cano, J.; Manzoni, P.; Palazzi, CE.; Ronzani, D. (2017). Flying ad-hoc network application scenarios and mobility models. International Journal of Distributed Sensor Networks. 13(10):1-17. doi:10.1177/1550147717738192S117131

Evaluation of the H.264 scalable video coding in error prone IP networks

The Joint Video Team, composed by the ISO/IEC Moving Picture Experts Group (MPEG) and the ITU-T Video Coding Experts Group (VCEG), has standardized a scalable extension of the H.264/AVC video coding standard called Scalable Video Coding (SVC). H.264/SVC provides scalable video streams which are composed by a base layer and one or more enhancement layers. Enhancement layers may improve the temporal, the spatial or the signal-to-noise ratio resolutions of the content represented by the lower layers. One of the applications, of this standard is related to video transmission in both wired and wireless communication systems, and it is therefore important to analyze in which way packet losses contribute to the degradation of quality, and which mechanisms could be used to improve that quality. This paper provides an analysis and evaluation of H.264/SVC in error prone environments, quantifying the degradation caused by packet losses in the decoded video. It also proposes and analyzes the consequences of QoS-based discarding of packets through different marking solutions

Communication Technologies Enabling Effective UAV Networks: A Standards Perspective

Recent developments in the unmanned aerial vehicles (UAVs) field have made evident the need for a standardization process of the communication technologies supporting direct information exchange, thus enabling UAV-to-UAV networking. We consider this is necessary to achieve all sorts of cooperative tasks requiring real-time (or near-real-time) synchronization, including swarm formation and collision avoidance. In this article, we therefore argue in favor of introducing a new standard that would address this specific area, highlighting why current technologies are not adequate, what the different steps toward rapid standardization are, and which lessons have been learned from related fields, namely the vehicular and robotic environments, in the past few years

Efficient content pushing in IEEE 802.11p vehicular environments

Vehicular networking is a new field that is expected to be widely adopted in the near future. One of the key applications inherent to this novel communications paradigm is content delivery to on-board users. In this paper we focus specifically on broadcast-based content delivery. We propose a content delivery scheme that is optimized for performance in order to improve the maximum amount of data than can be delivered, while also reducing delivery time to a minimum. With this goal our study combines both analytical and simulation results to determine the optimal packet size for content delivery so as to achieve the maximum throughput possible at different distances, and considering both static and mobile receivers. Experimental results show that our optimizations provide efficient delivery of multimedia contents for distances up to 200 meters when relying on IEEE 802.lip based broadcasting. Copyright © 2010 ACM

Peer-to-peer video streaming

The Internet as a video distribution medium has seen a tremendous growth in recent years. Currently, the transmission of major live events and TV channels over the Internet can easily reach hundreds or millions of users trying to receive the same content using very distinct receiver terminals, placing both scalability and heterogeneity challenges to content and network providers. In private and well-managed Internet Protocol (IP) networks these types of distributions are supported by specially designed architectures, complemented with IP Multicast protocols and Quality of Service (QoS) solutions. However, the Best-Effort and Unicast nature of the Internet requires the introduction of a new set of protocols and related architectures to support the distribution of these contents. In the field of file and non-real time content distributions this has led to the creation and development of several Peer-to-Peer protocols that have experienced great success in recent years. This chapter presents the current research and developments in Peer-to-Peer video streaming over the Internet. A special focus is made on peer protocols, associated architectures and video coding techniques. The authors also review and describe current Peer-to-Peer streaming solutions. © 2013, IGI Global

An efficient and robust content delivery solution for IEEE 802.11p vehicular environments

Vehicular networking is a new field that is expected to be widely adopted in the near future. One of the key applications inherent to this novel communications paradigm is content delivery to on-board users. In this paper we focus specifically on the design of a robust and efficient broadcast-based content delivery system. In order to reduce the content delivery time to a minimum, we first optimize performance by seeking the optimal packet size for content delivery. This goal is achieved by combining analytical and simulation results, and considering both static and mobile receivers at different distances from the transmitter. Moreover, we develop a full architecture that integrates the FLUTE protocol with different Forward Error Correction (FEC) schemes to achieve efficient content distribution. Through real experiments in a vehicular testbed we demonstrate that Raptor codes are the best option among the different FEC schemes available. In addition, as vehicle speed and/or distance from the broadcasting antenna increases, performance results highlight that adopting efficient FEC schemes becomes mandatory to achieve efficient and reliable data content delivery. (C) 2011 Elsevier Ltd. All rights reserved

Assessing the best strategy to improve the stability of scalable video transmission in MANETs

Mobile Ad Hoc Networks (MANETs) have been an important research topic for the last years, playing a crucial role within the fast growing sector of mobile communications. At the same time, video applications over mobile devices are becoming widely used by nowadays mobile clients, where the quality in the transmission of such contents will determine the success of these applications in the future. Therefore, it is mandatory to find the best strategies to guarantee a good Quality of Service (QoS) to the end-user. In this work we present a set of novel strategies to improve the performance of video transmission over MANETs. These new strategies are based on distributed admission control protocols which has proved to be helpful at achieving an efficient video transmission system. Experimental results show that, when adopting the new strategies to determine the optimal number of layers to transmit, we can achieve better results compared to other existent approaches in terms of idle time periods, fairness and delay. © 2011 IEEE