Search results for "Distributed"
showing 10 items of 1260 documents
Towards a Formal Analysis of MQtt Protocol in the Context of Communicating Vehicles
2017
International audience; The paper presents a formal approach to model, analyze, and verify a variant of Message Queue Telemetry Transport protocol (MQtt), dedicated to communicating vehicles (MQtt-CV) that send collected data to automotive infrastructures(subscribers). Our formal approach is based on Promela language and its system verification tool, the model checker SPIN. We propose a slight modification of MQtt protocol to reduce the big volume of data collected and sent by vehicles to infrastructures. Indeed, in the original version of MQtt protocol, when a broker receives data from publishers, it sends them directly to its subscribers without any filtration. As consequence, subscribers…
Concept of Client-Server Environment for Agent-Based Modeling and Simulation of Living Systems
2015
In the paper a concept for integrated and simple-to-use agent-based modeling and simulation environment is presented. The modeling environment allows simulating massive agent-based systems. Modeling environment itself is not domain specific, but it is expandable and allows creating domain-specific models. Hierarchical environment structure is supported. Individual agents could evolve by its individual path and pace. We use the General Living Systems theory as a reference model to check whether proposed modeling and simulation environment may also be used to describe models of living systems that are most complex systems around. The main concepts of proposed modeling environment such as agen…
The Random Neural Network Model for the On-line Multicast Problem
2005
In this paper we propose the adoption of the Random Neural Network Model for the solution of the dynamic version of the Steiner Tree Problem in Networks (SPN). The Random Neural Network (RNN) is adopted as a heuristic capable of improving solutions achieved by previously proposed dynamic algorithms. We adapt the RNN model in order to map the network characteristics during a multicast transmission. The proposed methodology is validated by means of extensive experiments.
An Efficient Distributed Algorithm for Generating Multicast Distribution Trees
2005
Multicast transmission may use network resources more efficiently than multiple point-to-point messages; however, creating optimal multicast trees (Steiner Tree Problem in Networks) is prohibitively expensive. For this reason, heuristic methods are generally employed. Conventional centralized Steiner heuristics provide effective solutions, but they are unpractical for large networks, since they require complete knowledge of the network topology. This paper proposes a distributed algorithm for the heuristic solution of the Steiner Tree Problem. The algorithm allows the construction of effective distribution trees using a coordination protocol among the network nodes. The algorithm has been i…
Enabling Retransmissions for Achieving Reliable Multicast Communications in WSNs
2016
To ensure end-to-end reliable multicast or broadcast transmissions in IEEE 802.15.4 based wireless sensor networks WSNs) is a challenging task since no retransmission and acknowledgment mechanisms are defined in such WSNs. In this paper, we propose three retransmission enabled multicast transmission schemes in order to achieve reliable packet transmissions in such networks. Different from the legacy CSMA/CA principle, these schemes allow a sending or forwarding node to retransmit a packet if necessary and enable implicit or/and explicit acknowledgment for multicast services. Simulations are performed in order to assess the performance of these schemes in terms of number of retransmissions, …
Evaluation and improvement of collective flooding in WSNs with various link correlations
2015
One of the main challenges confronted by wireless sensor networks (WSNs) is to reduce energy consumption of nodes for the purpose of network lifetime extension. In the literature, many backbone based protocols such as connected dominating set (CDS) and broadcast or multicast based protocols are employed in order to improve network performance in terms of metrics like energy consumption, number of transmissions and dissemination delay. In this paper, we evaluate the performance of a recently proposed transmission protocol known as collective flooding (CF), which is based on link correlation, under various link correlation conditions. Through simulations and analyses we demonstrate that altho…
Quality of Service Multicasting over Differentiated Services Networks
2003
This paper proposes a solution to support real-time multicast traffic with Quality of Service (QoS) constraints over Differentiated Services (DiffServ) IP networks. Our solution allows multicast users to dynamically join and leave the multicast tree. Moreover, it allows a multicast user which has negotiated a best-effort session to upgrade to a QoS-enabled session. Our solution is backward compatible with the Protocol Independent Multicast (PIM) scheme. It combines two ideas. First, resource availability along a new QoS path is verified via a probe-based approach. Second, QoS is maintained by marking replicated packets with a special DSCP value, before forwarding them on the QoS path.
KIND-DAMA: A modular middleware for Kinect-like device data management
2017
Summary In the last decades, we have witnessed a growing interest toward touchless gestural user interfaces. Among other reasons, this is due to the large availability of different low-cost gesture acquisition hardware (the so-called “Kinect-like devices”). As a consequence, there is a growing need for solutions that allow to easily integrate such devices within actual systems. In this paper, we present KIND-DAMA, an open and modular middleware that helps in the development of interactive applications based on gestural input. We first review the existing middlewares for gestural data management. Then, we describe the proposed architecture and compare its features against the existing simila…
Embedding Quantum into Classical: Contextualization vs Conditionalization
2014
We compare two approaches to embedding joint distributions of random variables recorded under different conditions (such as spins of entangled particles for different settings) into the framework of classical, Kolmogorovian probability theory. In the contextualization approach each random variable is "automatically" labeled by all conditions under which it is recorded, and the random variables across a set of mutually exclusive conditions are probabilistically coupled (imposed a joint distribution upon). Analysis of all possible probabilistic couplings for a given set of random variables allows one to characterize various relations between their separate distributions (such as Bell-type ine…
Clustering-Based Algorithm for Connectivity Maintenance in Vehicular Ad-Hoc Networks
2014
International audience; Among recent advances in wireless communication technologies' field, Vehicular Ad-hoc Networks (VANETs) have drawn the attention of both academic and industry researchers due to their potential applications including driving safety, entertainment, emergency applications, and content sharing. VANET networks are characterized by their high mobile topology changes. Clustering is one of the control schemes used to make this global topology less dynamic. It allows the formation of dynamic virtual backbone used to organize the medium access, to support quality of service and to simplify routing. Mainly, nodes are organized into clusters with at least one cluster head (CH) …