Performances, QoS et gestion de ressourcesdes réseaux sans fil dynamiques:




Axe: ComEx
Coordinateur : Michel MAROT
Objectif : Organisation de séminaire et échanges sur le thème des réseaux sans fil
Productions Scientifiques :
Financement Labex en : 2014/2015


Documents :



Présentation:
Ce groupe de travail se focalise sur les performances des réseaux sans fil, sur l'analyse de la QoS et la gestion de ressources dans le cas des réseaux dynamiques. Parmi ces types de réseaux sont considérés les réseaux ad-hoc, les réseaux mesh, les réseaux de capteurs, les réseaux hétérogènes, les réseaux véhiculaires, le Wireless-SDN, le sans-fil multisauts.... Les travaux sont menés dans des contextes technologiques et applicatifs pointus qui déterminent les contraintes des problèmes d’optimisation sous-jacents à l’allocation de ressources et exigent souvent une définition de la QoS spécifique. Les discussions porteront aussi sur les méthodes d'analyse de performance, la modélisation de la mobilité et l'impact de la mobilité sur ces systèmes, en particulier en termes de connectivité, de dimensionnement et de délais.



Le but de ce groupe de travail est d'être un lieu d'échanges sur cette thématique à travers la tenue de séminaires mensuels faisant intervenir à la fois les collègues du groupe et de leurs équipes ainsi que quelques chercheurs invités extérieurs.



Personnes concernées :







Sessions passées :



Table des matières




VENDREDI 25 SEPTEMBRE 2015 APRES-MIDI


Session du Groupe de Travail DigiCosme

"Performances, QoS et gestion de ressources des réseaux sans fil dynamiques"

Lieu : Amphi 33, bâtiment 862 – NanoInnov

Avenue de la Vauve

91120 PALAISEAU

(GPS : N. 48°42,7575', E. 02°11,5228')

Entrée libre

14h30-15h30: Luigi Aztori, Associate Professor at the Department of Electrical and Electronic Engineering at the University of Cagliari and Research Associate at the Multimedia Communications  Laboratory of CNIT, Italy - Titre: Trustworthiness and navigability in the social Internet of Things

The integration of social networking concepts into the Internet of Things has led to the Social Internet of Things (SIoT) paradigm, according to which objects are capable of establishing social relationships in an autonomous way with respect to their owners with the benefits of improving the network scalability in information/service discovery. After an introduction of the SIoT paradigm, this talk focuses on two problems: trustworthiness management and friendship selection. As to the trustworthiness management two models are discussed: in the subjective model each node computes the trustworthiness of its friends on the basis of its own experience and of the opinion of the friends in common with the potential service providers; in the objective model, the information about each node is distributed and stored making use of a distributed hash table structure so that any node can make use of the same information. As to the friendship selection, the major principle is to consider its impact on overall network navigability. The proposed heuristics are based on local network properties and on their impact on the overall network structure in terms of number of giant components, average degree of connections, local clustering and average path length.

 

Luigi Atzori is Associate Professor at the Department of Electrical and Electronic Engineering at the University of Cagliari (Italy) and Research Associate at the Multimedia Communications  Laboratory of CNIT (Consorzio Nazionale Interuniversitario per le Telecomunicazioni).

L. Atzori research interests are in computer networking, with particular emphasis on service management for Internet of Things and in wireless sensor networks, and multimedia communications, with a focus on multimedia QoE and wireless video streaming. L. Atzori is senior member of IEEE, chair of the Steering Committee of the IEEE Multimedia Communications Committee (MMTC) and co-chair of the IEEE 1907.1 standard on “Network-Adaptive Quality of Experience (QoE) Management Scheme for Real-Time Mobile Video Communications”. He is the coordinator of the European Marie Curie Initial Training Network on QoE for multimedia services (www.qoenet-itn.eu), which involves ten European Institutions in Europe and one in South Korea. He has been the editor for the ACM/Springer Wireless Networks Journal and guest editor for the IEEE Communications Magazine, the Springer Monet Journal and the Elsevier Signal Processing:  Image Communications  Journal. He is member of the editorial board of the IEEE IoT, the Elsevier Ad Hoc Networks and the Advances on Multimedia journals. He served as a technical program chair for various international conferences and workshops. He served as reviewer and panellist for many funding agencies, including FP7, Cost Action, Italian MIUR and Regional funding agency.



VENDREDI 19 JUIN APRES-MIDI

Lieu :
Amphi 34, bâtiment 862 – NanoInnov,
Avenue de la Vauve
91120 PALAISEAU
(GPS : N. 48°42,7575', E. 02°11,5228')

Entrée libre


Programme :



14h00-14h45: Marco Fiore, CNR Italie

Titre: Road traffic modeling with an eye to networking applications

The performance of protocols and architectures for upcoming connected vehicles are commonly investigated by means of computer simulations, due to the excessive cost and complexity of large-scale experiments. Dependable and reproducible simulations are thus paramount to a proper evaluation of vehicular networking solutions. Yet, we lack today a reference dataset of vehicular mobility scenarios that are realistic, publicly available, heterogeneous, and that can be used for networking simulations straightaway. In this talk, we present several contributions to the development of such a reference dataset, including (i) original synthetic traces that are generated from reliable sources, (ii) validation methodologies, and (iii) assessments of the potential impact of the traces on networking studies.


Presentation : Road Traffic Modeling With An Eye To Networking Applications


14h45-15h30: Alexandre Mouradian, L2S Université Paris Sud

Titre: Study of Probabilistic Worst Case Inter-Beacon Delays Under Realistic Vehicular Mobility Conditions

Road safety applications are one of the main incentives to deploy vehicular networks. These applications rely on periodic message exchange among vehicles (known as beaconing). The beacon messages contain information about the environment which is used to perceive dangerous situations and alert the drivers. The inter-beacon delay is the time between two consecutive beacons received from a car. It is an essential parameter because, if this delay exceeds the application requirement, the application cannot accurately predict dangerous situations and alert the drivers on time. The worst case inter-beacon delay has thus to be bounded according to the application requirements. Unfortunately, a tight and strict bound is in fact very difficult to obtain for a real network because of the randomness of the collisions among beacons coming from: the unpredictable mobility patterns, random interferences, randomness of the MAC layer backoff, etc.

We propose to provide a probabilistic worst-case of the inter-beacon delay under realistic mobility using Extreme Value Theory (EVT). EVT provides statistical tools which allow to make predictions on extreme deviations from the average of a parameter. These statistical predictions can be made based on data gathered from simulation or experimentation. We first introduce the EVT technique. Then we discuss its application to the study of inter-beacon delays. Finally, we apply EVT on the results of extensive vehicular network simulation using a realistic mobility trace: the Cologne trace.

Presentation : Study Of Probabilistic Worst Case Inter Beacon Delays Under Realistic Vehicular Mobility Conditions


15h30-16h15: Michel Marot, Telecom SudParis

Titre: On the Maximal Shortest Path in a Connected Component in V2V

We consider a VANET (Vehicular Ad-hoc NETwork) in a simple lane, without infrastructure. The arrivals of vehicles are assumed to be general with any traffic and speed assumptions. The vehicles communicate through the shortest path. We present results on the probability distribution of the number of hops on the maximal shortest path in a connected component of vehicles. The general formulation is given for any assumption of road traffic. Then, it is applied to calculate the z-transform of this distribution for medium and dense networks in the Poisson case. Our model is validated with the Madrid road traces of the Universitat Polit\`ecnica de Catalunya. These results may be useful for example when evaluating diffusion protocols through the shortest path in VANET, where not only the mean but also the other moments are needed to derive accurate results.

Presentation : On The Maximal Shortest Path In A Connected Component In V2V


VENDREDI 29 MAI 2015 APRES-MIDI

Lieu :
Amphi 34, bâtiment 862 – NanoInnov
Avenue de la Vauve
91120 PALAISEAU
(GPS : N. 48°42,7575', E. 02°11,5228')

Entrée libre



Programme :

14h00-15h00: Jim Roberts, IRT-SystemX
Titre : Multi-Resource Fairness: Objectives, Algorithms and Performance

Designing efficient and fair algorithms for sharing multiple resources between heterogeneous demands is becoming increasingly important. Applications include compute clusters shared by multi-task jobs and routers equipped with middleboxes shared by flows of different types. We show that the currently preferred objective of Dominant Resource Fairness (DRF) has a significantly less favorable efficiency-fairness tradeoff than alternatives like Proportional Fairness and our proposal, Bottleneck Max Fairness. We propose practical algorithms to realize these sharing objectives and evaluate their performance under a stochastic demand model. It is shown, in particular, that the strategyproofness property that motivated the choice of DRF for an assumed fixed set of jobs or flows, is largely irrelevant when demand is dynamic.

Presentation : Multi Resource Fairness: Objectives, Algorithms And Performance


15h00-16h00 : Aline Carneiro Viana, INRIA

Titre: Mobile Data Traffic Modeling: Revealing Temporal Facets

Todays’ smart handheld devices allow heterogeneous free data gathering of human surrounding environment and networking usage patterns anytime and anywhere. Hence, an unprecedentedly large amount of human sensory data (i.e., the Big Data era) can be collected and processed: opening ways to connect people, technology, and business. This big data implies advanced knowledge of humans’ behaviour and interactions at a planetary scale and can help tackle networking challenges when used correctly. In this presentation, I will briefly talk about my most recent works where I leverage behavior of networking users (in terms of interactions, mobility, or content generation) to improve the performance of networking solutions designed for data offloading or dissemination.

I will then provide more details about our work on user content behavior modeling: Measurement-driven modeling of mobile data traffic usage of smartphone subscribers, which was based on the use of a large-scale dataset collected from a major 3G network in a big metropolitan area. Our main outcome is a synthetic measurement based mobile data traffic generator, capable of imitating traffic-related activity patterns of different categories of subscribers and time periods of a routinary normal day in their lives. Broadly, our observations bring important insights into network resource usage.

Presentation : Mobile Data Traffic Modeling: Revealing Temporal Facets




VENDREDI 6 FÉVRIER 2015

Lieu :
AMPHI 34, BÂTIMENT 862 – NANOINNOV
Avenue de la Vauve
91120 PALAISEAU
GPS : N. 48°42,7575', E. 02°11,5228'

Entrée libre


Programme :

9H30-10H30: Nadjib Aitsaadi, Université de Paris-Est Créteil Val de Marne

Titre : Resource Allocation and Reliability within Cloud's Backbone Network

In this talk, I will address the resource allocation problem of Network as a Service (NaaS) within Cloud’s backbone. The main objective is to maximize the acceptance rate of virtual network requests while maximizing the quality of service and reliability of end-users. In doing so, the turnover of Cloud provider will grow up. I will detail three main resource provisioning strategies denoted by i) PR-VNE based on bee colony meta-heuristic, ii) CG-VNE based on artificial potential game theory and iii) BR-VNE based Monte-Carlo tree search.

Présentation: Resource Allocation And Reliability Within Cloud’s Backbone Network


10H30H-11H30 : Nicolas Thomas, UBUNTU

Titre: DESIGNING FOR SCALE AT DEVOPS SPEED DELIVERED: JUJU
This presentation will be made around a live demo on stage of the amazing capabilities Juju provides to deploy and operate in Cloud environment or to deploy the Cloud itself. http://juju.ubuntu.com 3 innovative concept to truly take advantage of the cloud technologies and API. Ready to drop pet for cattle, Juju is your Shepherd.

Présentation: JUJU OVERVIEW


11H30H-12H30 : François Frédéric Ozog, 6WIND

Titre: SCALE-UP STRATEGY FOR VCDN OR HOW TO GET UP TO 8X CDN CAPACITY ON THE SAME HARDWARE

La distribution de contenu statique (images, css, scripts...) et de média (films, audio...) peut dès aujourd'hui bénéficier de technologies qui permettent de multiplier la capacité d'un seul serveur tout en virtualisant l'application de distribution. 6WIND présentera des produits et "proof of concepts" qui permettent d'accélérer 10x la pile TCP/IP dans le guest, 8x l'accès au stockage et 10x la pile TCP/IP dans le host.

Deux benchmarks de technologies 6WIND serviront de fil conducteur (à notre connaissance, records mondiaux sur un seul serveur): d’une part 240Gbps de contenu web transmis sur le réseau à partir de 6,5M de requêtes HTTP/s avec 100M de connections simultanées (page moyenne de 4KB) et d’autre part 160Gbps de contenu stocké en Flash (approximativement 5MIOPS de 4KB) relayés sur le réseau

Enfin, l'état d'avancement du work item ETSI IFA002 qui traite des interfaces d'accélération des VNF sera présenté. Ce work item a été initié conjointement par Orange et 6WIND.

Présentation: SCALE UP STRATEGY FOR VCDN





VENDREDI 21 NOVEMBRE 2014 APRES-MIDI

Lieu :
Amphi 34, bâtiment 862 – NanoInnov
Avenue de la Vauve
91120 PALAISEAU
GPS : N. 48°42,7575', E. 02°11,5228'

Entrée libre


Programme :

14h-15h:Amine ADOUANE, Université de Versailles St-Quentin-en-Yvelines
Titre Game Theoretic Framework for Inter-Cell Interference Coordination

The exponential growth in the number of communications devices over the past decade has set out new ambitious targets to meet the ever-increasing demand for user capacity in emerging wireless systems. However, the inherent impairments of communication channels in cellular systems pose constant challenges to meet the envisioned targets. High spectral reuse efficiency was adopted as a solution to higher data rates. Despite its benefits, high spectral reuse leads to increased interference over the network, which degrades performances of mobile users with bad channel quality. To face this added interference, OFDM (Orthogonal Frequency Division Multiplexing) is used for the new 4th generation network. Thanks to its orthogonality OFDM eliminates the intra-cellular interference, but when the same resources are used in two adjacent cells, the inter-cell interference becomes severe. To get rid of the latter, several methods for Inter-Cell Interference Coordination (ICIC) have been proposed. ICIC allows coordinated radio resources management between multiple cells. The eNodeBs can share resource usage information and interference levels over the X2 interface through LTE-normalized messages. Non-cooperative game theory was largely applied were eNodeBs selfishly selects resource blocks (RBs) in order to minimize interference.

In this talk, we focus on ICIC for the downlink of a cellular OFDMA system in the context of the SOAPS (Spectrum Opportunistic Access in Public Safety) project. This project addresses low layers protocols issues for Broadband Services provision by PMR (Private Mobile Radio) systems using LTE technologies with particular focus on the improvement of frequency resource scheduling. Hence, our first work addresses the problem of downlink ICIC where the resource selection process is apprehended as a load balancing game for which we propose a fully decentralized algorithm. We adapt a stochastic version of a best-response dynamics algorithm to attain the pure Nash equilibria of the modeled game. Each eNodeB strives to select a pool of favorable resources with low interference based on local knowledge only. Proof of convergence is provided, and the efficiency of the tailored algorithm is proven through extensive simulations. In our second work, the ICIC issue was treated through adequate power allocation on RBs. The power level selection process of RBs is apprehended as a sub-modular game and a semi distributed algorithm based on best response dynamics is proposed to attain the NEs of the modeled game. Based on local knowledge conveyed by the X2 interface, each eNodeB will first select a pool of favorable RBs with low interference. Second, each eNodeB will strive to fix the power level adequately on those selected RBs realizing performances comparable with the Max Power policy that uses full power on selected RBs while achieving substantial power economy.

Présentation: GAME THEORETIC FRAMEWORK FOR INTER CELL INTERFERENCE COORDINATION

15h-16h : André-Luc BEYLOT, ENSEEIHT

Titre: Optimisation de bout-en-bout du démarrage des connexions TCP

Les protocoles de bout-en-bout tels que TCP souffrent lorsque l'un des liens présente des délais importants ce qui est par exemple le cas des communications par satellite. Nous montrons dans un premier temps dans cet exposé que les nouvelles versions de TCP telles que Compound ou Cubic améliorent sensiblement les performances pour les connexions longues mais restent toujours faibles pour les connexions courtes qui constituent encore de nos jours la majeure partie des communications.

Notre proposition se focalise donc sur le démarrage des connexions TCP. Une tentation forte est d'augmenter la fenêtre initiale même si cette proposition est controversée dans le cas de réseaux congestionnés. Nous suggérons alors d'augmenter la fenêtre initiale mais d'espacer les emissions dans cette première partie.

Nous montrons l'intérêt de notre proposition qui améliore sensiblement les performances et pas uniquement dans le cas d'étude initialement envisagé. Ces études ont d'abord été menées à l'aide de modèles mathématiques et de simulations.

La dernière partie de notre exposé porte sur l'implantation en vraie grandeur de notre proposition. Cette dernière nous a permis d'observer des phénomènes non pris en compte dans les simulateurs et de raffiner alors notre proposition.

Mots-clés : TCP, performances, implantation


Présentation: Understanding Cooperation Behavior In Information Dissemination In Vehicular Networks




VENDREDI 10 OCTOBRE 2014 APRES-MIDI

Lieu :
Amphi 34, bâtiment 862 – NanoInnov
Avenue de la Vauve
91120 PALAISEAU

Entrée libre



Programme

14h-15h: Naila BOUCHEMAL, Université de Versailles St-Quentin-en-Yvelines
Titre : MAC-LTE Scheduler Modeling and Performance Evaluation in LTE Network

Résumé : Long Term Evolution (LTE) is the most recent evolution of mobile phone standards; it has been proposed to provide higher throughput and better spectral efficiency. However with the increasing of services applications supported by each device in LTE networks, the resources sharing function is one of the key challenging issues. In this context, Logical Channel Prioritization (LCP) is referred. In this paper, we propose a mathematical model and performance evaluation of the Medium Access Control (MAC) layer scheduling algorithm while considering the source traffic characteristics, thus an original applications mapping. Our study highlights the impact of the Radio Resource Control (RRC) configuration on the overall performance during the Transport Block (TB) construction. Our analysis is based on a numerical study of a discrete time Markov chains and validated by an extensive simulation runs.

Presentation : MAC LTE Scheduler Modeling And Performance Evaluation In LTE Network



15h-16h : Jun ZHANG, Institut Mines-Télécom

Titre: Evaluation of Cooperation Behavior in Information Dissemination in Vehicular Networks

Résumé: Data diffusion in wireless vehicular networks relies on multi-hop relaying. In nature, relaying process in distributed networks is a cooperative act. We investigate the evolution of cooperation incentive in information dissemination in vehicular networks. In such networks, critical information, such as traffic jamming status, is broadcasted between vehicles. Each node (vehicle) in the network may choose two possible strategies: cooperation or defection. By cooperation, a node benefits its neighbors by broadcasting useful information, but costs itself by bandwidth utilization. By defection, a node can receive information from its neighbors without any cost. However, if all nodes defect, the system is trapped into a prisoner dilemma situation. We model the behavior of each node via evolutionary game theory (EGT), and present an EGT-based information dissemination scheme (EGID). The EGID scheme is evaluated from both theoretical analysis, and event driven simulation.

Presentation : Understanding Cooperation Behavior In Information Dissemination In Vehicular Networks




JEUDI 18, VENDREDI 19 SEPTEMBRE 2014


Workshop RA5G and
Digicosme RESEARCH ON NETWORK ARCHITECTURE AND MOBILITY MANAGEMENT IN 5G MOBILE SYSTEMS
in collaboration with Digicosme GT Perf/QoS/sans-fil dynamiques,
supported by Campus France, Digicosme and CEA at CEA Nano-Innov, France.

--------------------------


Programme:
Thursday, September 18th:


Friday, September 19th:


Speaker: Sofiane Imadali, CEA.

Title: VIN6: a VIN-based namespace for Evolutionary Future Vehicular Internet


Abstract: Vehicle communications are becoming increasingly popular thanks to car manufacturers and Public Transport Authorities investments. Standard development bodies (IEEE, C2C, ETSI, and ISO) introduced protocol stacks supporting Safety-related and non-safety related use cases. This talk focuses on the IPv6 layer, common to all SDOs stacks.

In the context of Future Internet and Locator/Identifier split paradigm, we propose to study the integration of vehicular communications in an evolutionary manner through the Vehicle Identifcation Numbers (VIN) namespace. In particular, we define the VIN-based IPv6 addressing and discuss its benefits for end-to-end services and its compatibility with the LISP approach.

On the other hand, dynamic IPv6 addressing and routing configuration in vehicular networks is another important challenge attracting a fair amount of attention. Early proposals adapted fixed-infrastructure and MANET models and thus inherited their latency and overhead. Later, researchers relaxed some of the often restrictive assumptions (e.g., Router Advertisement TTL extension) but still focused on certain limited scenarios. Along the Future Internet line of research, this presentation poses the terms of this problem in the IP-based vehicular communications area and aims at giving one solution space instance based on the Vehicle Identification Numbers namespace. In this presentation, (1) a comprehensive and detailed tutorial of the main approaches is presented. (2) The Future Internet paradigm as applied to vehicular networking, specifically through VIN namespace for group and infrastructure communications is introduced. (3) An analytical parameterized model to analyze and evaluate the proposals that fit best our communication paradigm is also presented.


Speaker: Haneul Ko, Korea University

Title: Research on Mobility and Network Architecture for 5G Systems

Abstract: Handover is a procedure that transfers an ongoing call from one cell to another as the user moves through the coverage area of a cellular system. In LTE/LTE-A networks, the data path switching is the default handover procedure. However, the data path switching has some problems such as high signaling overhead to core network entities and causing high delay jitter. The small coverage and massive deployment of femtocell intensify these problems. To solve this problem, important work is conducted in the literature. In this presentation, (1) Previous works are summarized to solve the problems of the data path switching and (2) We suggest optimized and distributed data packet forwarding scheme by using Markov decision process (MDP) to attain the optimal handover performance in LTE/LTE-A networks. We also introduce recent works on the network architecture for 5G systems.


Speaker: Insun Jang, Korea University

Title: Research on Collaborative Content Download in Mobile Collaborative Community

Abstract: Mobile collaborative community (MCC) is an emerging technology where multiple mobile nodes (MNs) conduct a job (e.g., large content download) in a cooperative manner.
In this presentation, I first introduce collaborative content download in which multiple MNs form MCC for content download through wireless wide area network (WWAN) and share of the downloaded content through wireless local area network (WLAN). Specifically, fundamental architecture and challenges, and existing works for collaborative content download are introduced. Next, I explain our proposed collaboration system, proxy-based collaboration system, where a contents proxy (CProxy) determines the amount of chunks scheduled to each MN and the received chunks are shared among MNs via WiFi Direct in a distributed manner. In the system, an optimization problem is formulated as a mixed integer nonlinear programming (MINLP) to minimize the total collaborative content download time and to solve the problem; a heuristic algorithm is presented.


Speaker: Sangheon Pack, Korea University

Title: Research Activity and Direction in Mobile Network and Communications Lab, Korea University

Abstract: In this talk, I will introduce the current research activities in Mobile Network and Communications Lab, Korea University. Specifically, four research categories:

  1. Future Networking Architecture for Mobility Management,

  2. Software-Defined Networking (SDN) and Network Function Virtualization,

  3. Emerging Mobile Services such as mobile cloud and mobile social
    networking, and

  4. Next-Generation WLANs and WMNs, are introduced and several
    collaboration topics are discussed.

    In addition, the current status for the joing co-research program between CEA LIST and Korea University/Sangmyung University, "Research on Network Architecture and Mobility Management in 5G Mobile Systems", is reported and future directions will be discussed.


    Speaker : Yvon Gourhant, Orange

Title: how to reduce operator costs for increasing Internet affordability

The emergence of Internet access and advanced wireless technologies has its limitations across the globe, i.e. today there exist several rural regions, especially in developing countries, that do not afford Internet connectivity.

In this talk, we will present two solutions that reduce operator costs for providing Internet affordable for all.

The first solution is a new business model and the design of a cost-effective wireless network architecture that aims at providing Internet in fix-usage within those countries. We claim that with few design changes to the 3GPP architecture, it is possible to extend Internet connectivity within suburban and rural areas by deploying numerous hotspots based on sharing tasks and revenues with local actors.

The second part of the talk is about dynamic sharing backhaul resources between operators in order to provide network survivability without investing extra-resources for setting up backup paths, but still keeping the competition at network level between operators. Our contribution is twofold. First, we will present multi-operator cooperative routing based on SDN (Software Defined Network) over maximally disjoint paths for the survivability of wireless backhaul. Second, we will deal with the problem of placing multiple centralized SDN controllers, among multiple network topologies, so as to maximize the resilience and scalability of such networks- within the bounds of convergence delay.



VENDREDI 13 JUIN 2014 APRES-MIDI


Lieu :

Amphi 33 – NanoInnov
Avenue de la Vauve
91120 PALAISEAU
GPS : N. 48°42,7575', E. 02°11,5228'

Entrée libre


Programme:

14h-15h : Anthony Busson, Université de Lyon 1
Titre: Modèle de géométrie stochastique pour le CSMA

Résumé: Les noeuds d'un réseau ad hoc partage en générale le même canal Wi-Fi. Ce canal peut être utilisé par plusieurs noeuds en même temps tant que leur distance est suffisamment grande afin d'éviter que les interférences soient trop importantes. Cet exposé présente des modèles spatiaux (à deux dimensions) et des modèles sur la ligne (pour les VANETs) qui vise à estimer cette réutilisation spatiale du medium. Nous montrerons que la capacité du réseau ad hoc est étroitement liée à ce phénomène."

Presentation : Modèle De Géométrie Stochastique Pour Le CSMA


15h-16h : Stéphane Pomportes, ESIEE-Amiens

Titre : Les modèles de mobilité dans l’évaluation de performances des protocoles de communication
Résumé : l’évaluation de performances est une étape indispensable de la conception d'un protocole de communication et permet entre autres de savoir si la solution proposée apporte une réelle plus value par rapport à l'existant. Généralement réalisées par simulation ces évaluations sont tributaires de la capacité de l'environnement de simulation à reproduire les contraintes d'un environnement réel. Or, si des phénomènes physiques tels que la propagation des ondes ou les interférences électromagnétiques sont relativement bien compris et modélisés, ce n'est pas forcément le cas pour le déplacement des unités dans un réseau dynamique.

Au cours de cet exposé, nous ferons tout d'abord un tour d'horizon des principaux modèles de mobilité existant afin de mieux comprendre le rôle de chacun d'entre eux. Nous verrons ensuite comment les propriétés intrinsèques de certains modèles peuvent influencer de manière inattendue l'évaluation de performances des protocoles.

Presentation : Modèles De Mobilité Dans L’évaluation De Performances Des Protocoles De Communication



VENDREDI 16 MAI 2014 APRES-MIDI



Lieu :
Amphi 34 – NanoInnov
Avenue de la Vauve
91120 PALAISEAU
(GPS : N. 48°42,7575', E. 02°11,5228')



Programme:

14h-15h : Joanna TOMASIK, Professeur à SUPELEC
Titre : Coloration de graphes au service de la sécurité nationale : coloration multiple et évaluée sur des graphes d’interférence
Résumé : Cet exposé présentera un problème d'allocation de ressources avec des contraintes de coloration dans des graphes modélisant les possibilités d'interférence au sein d'un réseau PMR (Private Mobile Radio), utilisé par les forces de l'ordre, l'armée.

Presentation : Coloration De Graphes Au Service De La Sécurité Nationale : Coloration Multiple Et évaluée Sur Des Graphes D’interférence




15h-16h : Sofiane Imadali, PhD candidate, CEA LIST, Communicating Systems Laboratory
Title: VIN6: a VIN-based namespace for Evolutionary Future Vehicular Internet

Abstract: Dynamic IPv6 addressing and routing configuration in vehicular networks is an important challenge that has attracted a fair amount of attention recently. Early proposals adapted fixed-infrastructure and MANET models and thus inherited their latency and overhead. Later, researchers relaxed some of the often restrictive assumptions (e.g., Router Advertisement TTL extension) but still focused on certain limited scenarios. Very recently, in the wake of the emerging concept of Future Internet, a general questioning arose on whether one naming and addressing model suits every network topology. Along this line of research, this presentation poses the terms of this problem in the IP-based vehicular communications area and aims at giving one solution space instance based on the Vehicle Identification Numbers namespace. In this presentation, (1) a comprehensive and detailed tutorial of the main approaches is presented. (2) The Future Internet paradigm as applied to vehicular networking, specifically through VIN namespace for group and infrastructure communications is introduced. (3) An analytical parameterized model to analyze and evaluate the proposals that fit best our communication paradigm is also presented. Depending on the audience, aspects related to privacy, large-scale deployment and revolutionary approaches (CCN-based) might be discussed.

Presentation : VIN6: A VIN Based Namespace For Evolutionary Future Vehicular Internet