Architecture à qualité de service pour systèmes satellites DVB-S/RCS dans un contexte NGN

L'objet de cette thèse est de doter les réseaux satellites d'accès géostationnaires d'une architecture de QoS compatible avec l'infrastructure NGN (Next Generation Network) qui entend réaliser la convergence des réseaux et services de communication existants et à venir. Dans une première étape, nous établissons un modèle de QoS NGN s'inspirant principalement de l'évolution des architectures de QoS dans les réseaux IP. Dans une deuxième étape, nous démontrons que les réseaux satellites ne disposent pas, en l'état actuel, d'une architecture de QoS suffisamment mature pour assurer un accès large bande aux futurs services IP multimédias. Afin d'y remédier, nous spécifions une architecture de QoS NGN unifiée assurant une étroite collaboration entre les mécanismes de QoS déployés à différents niveaux de communication (Application, Session, Réseau et MAC). Elle assure à la fois une différenciation de la QoS adaptée aux besoins des différentes classes d'applications au niveau IP tout en optimisant l'utilisation des ressources satellites via des mécanismes de bande passante à la demande au niveau MAC. Deux solutions applicatives assurant la corrélation dynamique entre les applications et les services réseaux différenciés sont également spécifiées et implémentées. Enfin un émulateur satellite de niveau réseau a été implémenté et nous a permis d'évaluer les garanties de QoS offertes par notre architecture et de valider leur conformité avec les besoins d'applications multimédias réelles. ABSTRACT : This thesis deals with the integration of geostationary access satellite networks in the NGN (Next Generation Network) infrastructure, a global QoS-enabled communication network based on IP. The first part depicts this multiservice ubiquitous infrastructure anchored on a clean separation between a transport/network domain and a service/application domain. Then a unified NGN control and management architecture, mainly inspired by the past and current IP QoS architectures, is proposed. In a second part, starting from this model and through a critical analysis of current DVB-S/RCS satellite systems, we demonstrate that satellite QoS architectures are not mature enough to support broadband access to future multimedia services and to integrate into the emerging NGN infrastructure. In order to cope with these issues, a NGNcompliant QoS architecture for DVB-S/RCS systems is defined. It relies on a cross-layer approach based on a tight interaction between QoS mechanisms available at different communication layers (Application, Session, Network and MAC). It aims at maximizing satellite capacity utilization at different granularity levels through a relevant configuration of DiffServ services using session/application signalling information and the use of optimized bandwidth on demand allocation schemes at the MAC layer. Application solutions (QoS Agent and QoS SIP Proxy) were developed while the satellite network with its associated QoS architecture was implemented through a network emulator. This latter enables us to evaluate the QoS guarantees provided by this architecture and to validate its appropriateness with real multimedia applications needs

Link Quality Metrics in Large Scale Indoor Wireless Sensor Networks

International audiencePouvoir estimer la qualité d'un lien sur la base d'un minimum de paquets est essentiel pour un réseau de capteur sans fil multisaut en environnement "indoor" compte tenu du coût énergétique de cette estimation et de ses conséquences sur la stabilité des routes construites sur ces liens. Notre étude s'appuie ainsi sur des expérimentations intensives menées sur une plateforme Senslab (\cite{www_senslab}) qui nous ont permis de trouver des lois de distribution suivies par les métriques physiques (RSSI, LQI) pour 3 catégories de liens (bons, mauvais, intermédiaires) regroupés par plage de PRR (Packet Reception Ratio). Sur la base de ces distributions, nous observons comment elles peuvent nous aider à discriminer les différents liens et ainsi les utiliser dans de futures expérimentations pour améliorer l'efficacité de protocoles de routage de réseaux de capteurs dans le choix des liens

Sustainable Traffic Aware Duty-Cycle Adaptation in Harvested Multi-Hop Wireless Sensor Networks

International audienceSustainable power management techniques in energy harvesting wireless sensors currently adapt the consumption of sensors to their harvesting rate within the limits of their battery residual energy, but regardless of the traffic profile. To provide a fairer distribution of the energy according to application needs, we propose a new sustainable traffic aware duty-cycle adaptation scheme (STADA) that takes into account the traffic load in addition to previous factors. We evaluate our protocol in the specific context of multi-hop IEEE 802.15.4 beacon-enabled wireless sensor networks powered by solar energy. Simulations show that our solution outperforms traffic-unaware adaptation schemes while minimizing the variance of the quality of service provided to applications

Topology Construction in RPL Networks over Beacon-Enabled 802.15.4

In this paper, we propose a new scheme that allows coupling beacon-enabled IEEE 802.15.4 with the RPL routing protocol while keeping full compliance with both standards. We provide a means for RPL to pass the routing information to Layer 2 before the 802.15.4 topology is created by encapsulating RPL DIO messages in beacon frames. The scheme takes advantage of 802.15.4 command frames to solicit RPL DIO messages. The effect of the command frames is to reset the Trickle timer that governs sending DIO messages. We provide a detailed analysis of the overhead incurred by the proposed scheme to understand topology construction costs. We have evaluated the scheme using Contiki and the instruction-level Cooja simulator and compared our results against the most common scheme used for dissemination of the upper-layer information in beacon-enabled PANs. The results show energy savings during the topology construction phase and in the steady state

Energy Consumption and Performance of IEEE 802.15.4e TSCH and DSME

International audienceThe recent IEEE 802.15.4e standard has introduced two interesting modes of operation: Time Slotted Channel Hopping (TSCH) and Deterministic and Synchronous Multi-channel Extension (DSME). Both provide a mix of time and frequency division to improve the performance of the previously available synchronized MAC mode (beacon-enabled 802.15.4). In this paper, we compare the performance of DSME and TSCH with respect to the energy consumption, throughput, and delay through an analysis of their respective ways of operation. We use an energy consumption model coming from our previous experience on the design of recent energy harvesting motes for the GreenNet platform. Our results show that DSME performs slightly better in terms of the energy consumption spent in data transfers. Both protocols exhibit similar delays for a given duty cycle, nevertheless, TSCH obtains shorter delay and higher throughput for low duty cycles. For higher duty cycles, TSCH results in lower throughput—for applications that send little data, the fixed slot configuration of TSCH results in wasted bandwidth. DSME can allocate shorter slots, which is beneficial for applications that transmit short packets

Architecture à qualité de service pour systèmes satellites DVB-S/RCS dans un contexte NGN

L'objet de cette thèse est de faciliter l'intégration des systèmes satellites DVB-S/RCS dans la future infrastructure de communication NGN (Next Generation Network). Après avoir défini un modèle d'architecture de contrôle NGN et établi un état de l'art sur les systèmes satellites DVB-S/RCS, nous démontrons que les réseaux satellites ne disposent pas, en l'état actuel, d'une architecture de QoS suffisamment mature pour assurer un accès large bande aux futurs services IP multimédias. Pour y remédier, nous spécifions une architecture QoS NGN pour les systèmes DVB-S/RCS assurant une étroite collaboration entre les mécanismes de QoS déployés à différents niveaux de communication (Application, Session, Réseau et MAC). Enfin, les garanties de QoS offertes par notre architecture sont évaluées à partir d'un émulateur satellite réseau ce qui nous a permis de valider leur adéquation avec les besoins d'applications multimédias réelles.This thesis deals with the integration of geostationary access satellite networks in the NGN (Next Generation Network) infrastructure, a global QoS-enabled communication network based on IP. At first, a NGN control and administration architecture model is defined. Then a critical analysis of current DVB-S/RCS satellite systems puts the emphasis on their inability to support broadband access to future multimedia services and to integrate into the emerging NGN infrastructure. In order to cope with these issues, a NGN-compliant QoS architecture for DVB-S/RCS systems is defined. It relies on a tight interaction between QoS mechanisms available at different communication layers (Application, Session, Network and MAC). This architecture was implemented in a satellite network emulator which enables us to evaluate the QoS guarantees provided by this architecture and to validate its appropriatness with real multimedia applications needs.TOULOUSE-ENSEEIHT (315552331) / SudocSudocFranceF

Satellite and next generation networks : QoS issues

International audienceBroadband satellite systems will need specific functions and interfaces in order to fit seamlessly into an end-to-end Next Generation Network (NGN) Quality of Service (QoS) architecture. This paper will define NGN overall architecture, showing how the coupling between Application/session layers and Network/transport layers can achieve end-to-end QoS support. Possible integration scenarios of satellite access into such architectures will be depicted, with a special emphasis on transparent and regenerative satellite architectures based on DVB-RCS [14] type of access. Detailed architectures proposed by two recent research projects, IST Satellite Broadband Multimedia System for IPv6 (SATIP6) [21] and ESA Integrated Resources and QoS Management in DVB-RCS networks (QoSforRCS) [11] [7], will be presented. On the one hand, we will develop a “QoS assured” architecture proposed in the frame of QoSforRCS: it provides dynamic Service Level Agreement (SLA) management and strict QoS control. Admission Control (AC) function is located in the satellite Hub which allows fine control and billing by the Service Providers. On the other hand, a “QoS enabled” architecture proposed in the frame of SATIP6 is presented: it allows simple QoS differentiation between applications based on configuration by the end user or the subscriber's network administrator. This architecture may include AC function and is designed for Virtual Private Network (VPN) deployment

QoS Architecture over DVB-RCS satellite networks in a NGN framework

International audienceGeostationary satellite networks are currently considered as one of the most promising broadband access network technology for narrowing the digital divide. Though technically attractive and cost effective, the provisioning of end-to-end QoS services in satellite access remains largely undefined for the Next Generation Networks (NGN). In order to bridge this gap, the European SATIP6 project defines a complete QoS architecture involving Application, Session, Network and Link layers over DVB-S/RCS (Digital Video Broadcasting via Satellite/Return Channel via Satellite) systems which is detailed in this paper. First, a review of DVB-RCS standard approaches to QoS in satellite networks is given. Then we focus on the proposed QoS architecture layer by layer: the MAC layer taking benefits from DVB-RCS dynamic allocation schemes, the IP layer implementing differentiated services and finally two separate solutions, at Application/Session layers, for applications to take advantage of the QoS architecture developed on the satellite segment

Signalisation de QdS dans un réseau satellite de nouvelle génération

International audienceLes avancés conjuguées des transmissions et du codage ont permis l'apparition de d'un nouveau type de réseaux satellites géostationnaires. Avec une voie de retour par satellite et des mécanismes de commutation à bord, ces systèmes dédiés aux communications multimédia large bande sont conçus pour intégrer dans un futur proche l'offre des réseaux de nouvelle génération. Les enjeux majeurs de tels systèmes sont la fourniture de services évolués tels que la qualité de service (QdS), la diffusion ou la sécurisation des communications. Cet article présente l'implémentation d'une architecture DiffServ sur un réseau satellite de type DVB-S/RCS et détaille plus particulièrement les mécanismes de signalisation de la QdS. Ces fonctionnalités ont été implantées et testées dans une plateforme d'émulation satellite développée dans le cadre du projet européen Satip6

Link Quality Estimation with the Gilbert-Elliot Model for Wireless Sensor Networks

International audienceIn this paper, we apply the Gilbert-Elliot model to analyze measurements on a large-scale wireless sensor testbed with nodes equipped with CC1101 and CC2420 radio chips. The model considers a packet loss process as a sequence of transitions between Good and Bad states. We analyze the Packet Reception Ratio (PRR) based on the probabilities derived from the Gilbert-Elliot model. We show that the probabilities and other parameters (run and loss lengths) can very well discriminate between the main categories of link quality such as good and weak links. Identification of link quality is crucial for routing protocols such as RPL and LOADng