Dealing with Heterogeneity in a Fully Reliable Multicast Protocol

Many of the proposed multicast congestion avoidance algorithms are single-rate where heterogeneity is accommodated by adjusting the transmission rate as a response to the worst receiver in the group. Due to the Internet heterogeneity, a single-rate congestion co ntrol affects the overall satisfaction of the receivers in a multicast session. In this paper, we propose a multi-rate replicated scheme where some receivers (instead of the source) are designated to perform data replication for other receivers with lower capacity. To be more scalable and to minimize the bandwidth consumption due to data replication, the partitioning algorithm is per- formed on-the-fly by the routers depending on the feedback they receive. Neither a prior estimation of the receivers capacity is necessary nor a complex computation is required to execute our partitioning algorithm

A RTT-based Partitioning Algorithm for a Multi-rate Reliable Multicast Protocol

Various Internet applications involve multiple parties and usually adopt a one-to-many communication paradigm (multicast). The presence of multiple re ceivers in a multicast session rises the problem of inte¡ r-receiver fairness. Transmitting with a rate which matches the slowest receiver will limit the throughput of other receivers and thus their satisfaction. A multi-rate mechanism where the receivers are distributed into subgroups with similar capacities, can improve the inter-receiver fairness for multicast sessions. In this paper, we deal with the problem of receivers partitioning and propose a simple algorithm based on the receivers RTT variations where an explicit estimation of the receivers capacities is avoided. Our partitioning algorithm, although simple, performs an on-the-fly partitioning depending on the receivers' feedback. We show that our partitioning algorithm approximates and in many cases, achieves the optimal solution with a minimum computation effort

Dealing with Heterogeneity in an Active-based Multicast Congestion Avoidance Protocol

Many of the proposed multicast congestion avoidance algorithms are single-rate where heterogeneity is accommodated by adjusting the transmission rate as a response to the worst receiver in the group. Due to the Internet heterogeneity, a single-rate congestion control affects the overall satisfaction of a multicast session receivers. In this report, we propose a multi-rate replicated scheme where some receivers (instead of the source) are designated to perform data replication for other receivers with lower capacity. To be more scalable and to minimize the bandwidth consumption due to data replication, the partitioning algorithm is performed on-the-fly by the routers depending on the feedbacks they receive. Neither a prior estimation of the receivers capacity is necessary nor a complex computation is required to execute our partitioning algorithm

An Active Reliable Multicast Framework for the Grids

Computational Grids are foreseen to be one of the most critical yet challenging technologies to meet the exponentially growing demands for high-performance computing in a large variety of scientific disciplines. Most of these grid applications imply multiple participants and in many cases make an intensive usage of data distribution and collective opertaions. In this paper, we propose a multicast framework consisting of an active reliable protocol with specialized active services located at the edges of the core network for providing low-latency and low-overhead multicast transfers on computational grid

Cluster-based Routing Protocols for Energy-Efficiency in Wireless Sensor Networks

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Load Repartition for Congestion Control in Multimedia Wireless Sensor Networks with Multipath Routing

Wireless sensor networks hold a great potential in the deployment of several applications of a paramount importance in our daily life. Video sensors are able to improve a number of these applications where new approaches adapted to both wireless sensor networks and video transport specific characteristics are required. The aim of this work is to provide the necessary bandwidth and to alleviate the congestion problem to video streaming. In this paper, we investigate various load repartition strategies for congestion control mechanism on top of a multipath routing feature. Simulations are performed in order to get insight into the performances of our proposals

A Loss Detection Service for Active Reliable Multicast Protocols

Reliable multicast protocols have gained popularity with active service contributions where routers implement additional functionalities. Reducing the delay of recovery is one of the desirable features of a reliable multicast protocol. In this paper we propose an active-based architecture with specialized routers. Using simulations we show how this architecture with the proposed services (mainly the loss recovery from the receivers and the loss detection at the routers), could improve the performances of a reliable multicast application in term of the recovery delay

A RTT-based Partitioning Algorithm for a Multi-rate Reliable Multicast Protocol

Various Internet applications involve multiple parties and usually adopt a one-to-many communication paradigm (multicast). The presence of multiple receivers in a multicast session rises the problem of inter-receiver fairness. Transmitting with a rate which matches the slowest receiver will limit the throughput of other receivers and thus their satisfaction. A multi-rate mechanism where the receivers are distributed into subgroups with similar capacities, can improve the inter-receiver fairness for multicast sessions. In this report, we deal with the problem of receivers partitioning and propose a simple algorithm based on the receivers RTT variations where an explicit estimation of the receivers capacities is avoided. Our partitionin- g algorithm, although simple, performs an on-the-fly partitioning depending on the receivers' feedback. We show that our partitioning algorithm approximates and in many cases, achieves the optimal solution with a minimum computation effort.Une grande variété d'applications impliquent la participation de plusieurs entités, ainsi un paradigme de communication one-to-many (multicast) y est le plus adapté. La présence de plusieurs récepteurs dans une session de multicast soulève le problème de l'équité inter-récepteurs. L'émission avec le débit du récepteur le plus lent limita sans doute la satisfaction des autres récepteurs; Un mécanisme multi-débit où les récepteurs sont partitionnés sur des sous-groupes de capacités similaires, pourrait améliorer considérablement l'équité inter-récepteur. dans ce rapport, nous traitons le problème du partitionnement des récepteurs et proposons un algorithme simple basé sur les variations du RTT des différents récepteurs. une estimation explicite des capacités des récepteurs est ainsi évitée. Notre algorithme de partitionnement fait un partitionnement à-la-volée en fonction des messages de contrôle provenant des récepteurs. on montre que l'algorithme proposé approche e dans plusieurs cas atteint la solution optimale avec une complexité minimal

Active Reliable Multicast Strategies for Internet-based Grid Computing Infrastructures

Reliable multicast requires that all packets are safely delivered to the destinations. Such communication patterns are in-tensively used in the so-called grid computing infrastructure where many computing resources are spread over the Internet to offer to the users the access to a huge amount of computational power. However, meeting the objectives of reliable multicast is not an easy task and this paper presents active solutions that aim to reduce the end-to-end latency and to increase the achievable throughput of reliable multicast protocols for grid computing over the Internet. More specifically, the performances of several active mechanisms such as NACK aggregation and subcasting are investigated

Une approche d'ontologie pour la modélisation des connaissances et l’interrogation des capteurs de réseaux sans fil

International audienceWireless sensor networks (WSNs) generate large volumes of raw data which increases the difficulty for applications to manage and query sensor data. WSNs are normally application specific with no sharing or reusability of sensor data among applications. In order for applications to be developed independently of particular WSNs, sensor data need to be enriched with semantic information. Ontologies are widely used as a means for solving the information heterogeneity problems because of their capability to provide explicit meaning to the information. This paper presents our work towards the development of a wireless sensor network ontology. Based on the proposed ontology we use the SPARQL query language to enable querying of sensor data. We present the description of the development of the proposed ontology, partial evaluation of the early prototype ontology, a discussion of design and implementation issues, and directions for future research works.Les réseaux de capteurs sans fil (WSN) génèrent de gros volumes de données brutes, ce qui complique la gestion et l'interrogation des données des capteurs par les applications. Les WSN sont normalement spécifiques à une application, sans partage ni possibilité de réutilisation des données de capteur entre les applications. Pour que les applications puissent être développées indépendamment de certains WSN, les données des capteurs doivent être enrichies d'informations sémantiques. Les ontologies sont largement utilisées pour résoudre les problèmes d'hétérogénéité de l'information en raison de leur capacité à donner un sens explicite à l'information. Cet article présente nos travaux en vue du développement d’une ontologie de réseau de capteurs sans fil. Sur la base de l'ontologie proposée, nous utilisons le langage de requête SPARQL pour permettre l'interrogation des données du capteur. Nous présentons la description du développement de l'ontologie proposée, une évaluation partielle de l'ontologie du prototype initial, une discussion des problèmes de conception et de mise en œuvre et des orientations pour les travaux de recherche futurs