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A sensor network is composed of a given number of communicating sensors, which aims to collect data from their envirenement. When interesting events are detected, information is routed from one node to another and eventually gathered in... more
A sensor network is composed of a given number of communicating sensors, which aims to collect data from their envirenement. When interesting events are detected, information is routed from one node to another and eventually gathered in gateway nodes or base stations. Recently, sensors have become a promising operational technology for underwater environment. For example, they are now able to collect accurately several water quality parameters such as; temperature, chemical substances, water density etc. Another major technological advance of underwater sensors technology is the improvement in their communication capability. For instance, many underwater sensors are now able to exchange data through acoustic waves. As a result of this evolution, underwater sensors could now be organized as an autonomous communicating network. UnderWater Sensors Network (UWSN) is a very recent network topic. Since very few years, it attracts a growing interest from the network community. The underwater context offers to the community the possibility to design and to imagine new applications. Potential applications domain includes, military surveillance (e.g. leak detection), ecology (e.g. water quality and biological monitoring) and public safety (e.g. seismic and tsunami monitoring) etc. Moreover, the particularity of the underwater context (e.g. the long delay related to the acoustic communication technology) offers to the community new interesting challenges. Recent works have addressed some of the identified issues. Since UWSN is a new emerging network topic, up to now, most of researches have mainly focused on fundamental sensor networking problems such as routing protocols, energy minimization, delocalization, and data gathering. But, a lot still have to be done in order to obtain low cost operational UWSN. Suitable deployment of under water sensors for efficient monitoring is among these crucial issues. In the best of our knowledge, deployment of sensors has been addressed mainly in terrestrial networks. Most of works assume a random geographical sensors deployment within a target area. This assumption holds for a non-accessible area
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The throughput supported by network interfaces can be hardly followed by the packet processing speed in software. The processing rate is bounded due to the overheads imposed by the architecture of the network stack. For this reason,... more
The throughput supported by network interfaces can be hardly followed by the packet processing speed in software. The processing rate is bounded due to the overheads imposed by the architecture of the network stack. For this reason, multiple research proposals try to offload packet processing on different types of hardware like GPUs and FPGAs. In this paper we present an architecture which offloads the data plane packet processing on a programmable hardware with parallel processing capability. For this purpose, we use the MPPA (Massively Parallel Processor Array) smart NIC from Kalray which offers the ODP API that can be used for packet processing. Our goal is to build a full mesh non-blocking layer 2 network. We implemented a TRILL protocol on the MPPA processor, which can be used as a basis for fabric network, but some other protocol may be used as well. Our performance evaluation shows that we can process TRILL frames at full-duplex line-rate (up to 40Gbps) for different packet sizes while reducing latency.
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This document describes an architecture based on the Host Identity Protocol (HIP), for active RFIDs, i.e. Radio Frequency Identifiers inluding tamper resistant computing resources, as specified for example in the ISO 14443 or 15693... more
This document describes an architecture based on the Host Identity Protocol (HIP), for active RFIDs, i.e. Radio Frequency Identifiers inluding tamper resistant computing resources, as specified for example in the ISO 14443 or 15693 standards. HIP-RFIDs never expose their identity in clear text, but hide this value (typically an EPCCode) by a particular equation (f) that can be only solved by a dedicated entity, referred as the portal. HIP exchanges occurred between HIP-RFIDs and portals; they are shuttled by IP packets, through the Internet cloud.
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In this paper, we propose a novel 3D Underwater Wireless Sensor Network Deployment scheme for solid detection in rivers. Our objective is to minimize the number of deployed underwater sensors within a target field installation while... more
In this paper, we propose a novel 3D Underwater Wireless Sensor Network Deployment scheme for solid detection in rivers. Our objective is to minimize the number of deployed underwater sensors within a target field installation while ensuring i) the required Quality of Monitoring (QoM) (i.e., differentiated probabilistic detection) and ii) wireless network connectivity. To generate the best topology, we propose a novel deployment heuristic, named 3D-UWSN-Deploy, based on a subcube tessellation of the monitored field installation and a mixed integer linear program optimization. To gauge the effectiveness of 3D-UWSN-Deploy, we compare it with the most prominent related strategies. Simulation results show that our proposal is scalable and obtains the best performance in terms of cost deployment, quality of monitoring and connectivity.
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The analysis and construction of a communication network with a very high bandwidth (approximately 1 Giga-bit per second using fiber optics) are discussed. Two applications being considered for this multipurpose network are a high quality... more
The analysis and construction of a communication network with a very high bandwidth (approximately 1 Giga-bit per second using fiber optics) are discussed. Two applications being considered for this multipurpose network are a high quality multiservice telephone, and a documentary system which creates digital archives. The topology adopted is a ring. The communication medium and the frame structure are described,
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With current network simulators, simulation results are obtained from flat trace files via sequential data access. To speed up simulation output analysis, we propose to store the simulation traces into data warehouse. Our proposed... more
With current network simulators, simulation results are obtained from flat trace files via sequential data access. To speed up simulation output analysis, we propose to store the simulation traces into data warehouse. Our proposed framework relies on a three-layer architecture, with the intermediary database layer serving the trace file post processing services. The trace files are accessed through SQL-like queries
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This survey gives a comprehensive review of recent advances related to the topic of VoIP QoE (Quality of user' Experience). It starts by providing some insight into the QoE arena and outlines the principal building blocks... more
This survey gives a comprehensive review of recent advances related to the topic of VoIP QoE (Quality of user' Experience). It starts by providing some insight into the QoE arena and outlines the principal building blocks of a VoIP application. The sources of impairments over data IP networks are identified and distinguished from signal-oriented sources of quality degradation observed over
Research Interests: Computer Science, Distributed Computing, Voice over IP, Quality of Experience, Voice Conversion, and 11 moreQuality of Service, Quality assessment, IP networks, Packet Loss, Transportation Networks, Automatic Assessment, service Business, Electrical And Electronic Engineering, Heterogeneous Network, Time varying, and Parametric Model
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A distribuição do controle em Redes Definidas por Software melhora a segurança, o desempenho e a escalabilidade da rede ao custo de novos desafios para a consistência da visão global da rede. Este trabalho apresenta as principais ameaças de... more
A distribuição do controle em Redes Definidas por Software melhora a segurança, o desempenho e a escalabilidade da rede ao custo de novos desafios para a consistência da visão global da rede. Este trabalho apresenta as principais ameaças de segurança às redes definidas por software, propõe um mecanismo de autenticação e controle de acesso de estações finais baseado na credencial da estação, propõe uma arquitetura eficiente de distribuição de controladores e esquemas consistentes para a atualização de políticas em redes com controle centralizado ou distribuído. A avaliação das propostas é realizada através de protótipos, modelos formais e simulações. Os resultados demonstram que a proposta de controlador distribuído é eficiente na instalação e localização das instâncias dos controladores. As simulações dos esquemas de atualização de políticas mostram que o desempenho das propostas são superiores aos literatura nos cenários tanto com controle centralizado como distribuído.
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Int. J. Internet Protocol Technology, Vol. 3, No. 1, 2008 13 SLA-based dynamic resource management in wireless environments: an enterprise nomadism use case
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Energy consumption of communication systems is becoming a fundamental issue and among all the sectors, wireless access networks are largely responsible for the increase in consumption. With this increasing demand for energy in wireless... more
Energy consumption of communication systems is becoming a fundamental issue and among all the sectors, wireless access networks are largely responsible for the increase in consumption. With this increasing demand for energy in wireless field related with the increase in carbon dioxide levels in the environment produced by wireless devices in the idle mode, it is very essential to develop the technology that reduce energy consumption. In this context, Wireless Mesh Networks (WMNs) are commonly considered as the most suitable architecture because of their versatility that allows flexible configurations. Different studies have proposed number of protocols in different layers of TCP/IP model to enhance transmission of data. Very few of these protocols envisage node energy. This paper mainly focuses on classification layer of the largest existing approaches dedicated to energy conservation. Keywords-WMN; 802.11s; Energy consumption; TCP/IP layers, Topology control; Power control; Sleep.
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ABSTRACT This paper presents a new congestion management scheme intended to control cell loss in ATM switches. Most of the research propositions tackling the congestion control, focus on the ATM layer only. Our mechanism is based on the... more
ABSTRACT This paper presents a new congestion management scheme intended to control cell loss in ATM switches. Most of the research propositions tackling the congestion control, focus on the ATM layer only. Our mechanism is based on the utilization of both AAL and ATM features and on a particular definition of the priority bit. Whenever one cell of a message overflows the buffer of an ATM switch, the algorithm causes the switch to discard other cells of the message (including later arrivals). Such discarding frees buffer space for cells of other messages that have a chance of arriving at their destination intact. Our objective is to emphasize that in case of overload, cells are discarded without any semantic information about the type of cells. So, at the destination, all the fragments of the corrupted messages will be discarded anyway because the ATM layer cannot detect cell losses and does not provide selective cell retransmission mechanisms. Finally, we present simulation results comparing c...
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This paper addresses the issue of wireless resource allocation of a Mobile WiMAX cell based on OFDMA access technique. We compare two strategies: the MAX SNR which is the most used channel assignment technique and our proposal which is... more
This paper addresses the issue of wireless resource allocation of a Mobile WiMAX cell based on OFDMA access technique. We compare two strategies: the MAX SNR which is the most used channel assignment technique and our proposal which is based on channel condition learning. As we distinguish four IEEE 802.16e-2005 service classes: UGS, rtPS, nrtPS and ErtPS, we combine these strategies with a scheduler block in order to satisfy the QoS constraints of these classes. In addition, we take into consideration the Adaptive Modulation and Coding (AMC) scheme, through the selection of the slot which is based on the modulation scheme. The main concern here is to propose a simple method to assign WiMAX physical resources called slot to satisfy QoS constraints of a user's scheduled MPDUs, which can be easily and efficiently used in a realistic Mobile WiMAX network.
Research Interests: Computer Science, Resource Allocation, OFDM, Computer Network, Quality of Service, and 12 moreWimax, Adaptive modulation, Physical Layer, Resource Management, Link Adaptation, Boolean Satisfiability, Dynamic Channel Allocation, Adaptive Modulation and Coding, Channel assignment, Downlink, Channel Allocation, and OFDM modulation
ABSTRACT In this paper, we propose a mathematical model with the aim to give guidelines for the dimensioning of WiMax bandwidth provisioning service to residential customers. Our proposal relies on the modeling of a CAC policy associated... more
ABSTRACT In this paper, we propose a mathematical model with the aim to give guidelines for the dimensioning of WiMax bandwidth provisioning service to residential customers. Our proposal relies on the modeling of a CAC policy associated to a priority-based bandwidth sharing strategy. Both mechanisms aim to satisfy Quality of Service constraints while maximizing the gain of the system. But unlike in , we do not necessarily seek here for an optimal CAC policy. We rather consider a coordinate convex CAC policy, whose mathematical modeling leads to a tractable analytical resolution. We chose the Guaranteed Minima (GM) policy, which consists in reserving a specified amount of bandwidth for each traffic class. The remaining bandwidth is shared between all traffic classes.