Adaptive and occupancy-based channel selection for unreliable cognitive radio networks

In this paper, we propose an adaptive and occupancy-based channel selection for unreliable cognitive radio networks

Toward Reliable Contention-aware Data Dissemination in Multi-hop Cognitive Radio Ad Hoc Networks

This paper introduces a new channel selection strategy for reliable contentionaware data dissemination in multi-hop cognitive radio network. The key challenge here is to select channels providing a good tradeoff between connectivity and contention. In other words, channels with good opportunities for communication due to (1) low primary radio nodes (PRs) activities, and (2) limited contention of cognitive ratio nodes (CRs) acceding that channel, have to be selected. Thus, by dynamically exploring residual resources on channels and by monitoring the number of CRs on a particular channel, SURF allows building a connected network with limited contention where reliable communication can take place. Through simulations, we study the performance of SURF when compared with three other related approaches. Simulation results confirm that our approach is effective in selecting the best channels for efficient and reliable multi-hop data dissemination

Activity Pattern Impact of Primary Radio Nodes on Channel Selection Strategies

International audienceThe performance of cognitive radio network is highly dependent upon the primary radio nodes activity pattern. In this paper, we study and analyze the impact of different PR nodes activity pattern with the help of three performance metrics. In this perspective, we use our channel selection strategy SURF and three other channel selection strategies i.e., Random (RD), Highest Degree (HD), and Selective Broadcasting (SB). We analyze the performance of these channel selection strategies through extensive NS-2 simulations. Moreover, we also analyze how these strategies respond to different PR nodes activity. Simulation results confirm that SURF outperforms RD, HD, and SB in terms of delivery ratio and causes less harmful interference to PR nodes, in all primary radio nodes activity pattern

SURF: A Distributed Channel Selection Strategy for Data Dissemination in Multi-Hop Cognitive Radio Networks

In this paper, we propose an intelligent and distributed channel selection strategy for efficient data dissemination in multi-hop cognitive radio network. Our strategy, SURF, classifies the available channels and uses them efficiently to increase data dissemination reliability in multi-hop cognitive radio networks. The classification is done on the basis of primary radio unoccupancy and of the number of cognitive radio neighbors using the channels. Through extensive NS-2 simulations, we study the performance of SURF compared to three related approaches. Simulation results confirm that our approach is effective in selecting the best channels for efficient communication (in terms of less primary radio interference) and for highest dissemination reachability in multi-hop cognitive radio networks

Reasoning Services for Security and Energy Management in Wireless Sensor Networks

Abstract-In this paper we propose a management scheme based on automated reasoning for wireless sensor networks. Our scheme ensures reliable zone surveillance with reduced energy consumption, a crucial constraint in sensors networks and in tomorrow's green communication platforms. We divide the zone to monitor into a set of areas each containing a management node that implements reasoning services. The management node centralizes alerts issued by sensors in the area, correlates them, and raises an alarm to the administrator only if a real event occurs. Moreover, each sensor runs a set of reasoning functions that limit its communication with the management node of its area. Through simulations we show that our scheme reduces considerably the number of messages sent from sensor to management nodes as well as alarms raised by the management nodes to the administrator without missing events in the monitored zone. Hence our management ensures reliable surveillance and extends the sensor network lifetime in the same time

Toward Reliable Contention-aware Data Dissemination in Multi-hop Cognitive Radio Ad Hoc Networks

This report was first published as: INRIA RR-0375, 2009, France. http://hal.inria.fr/inria-00441892/en/. Now, the report number is changed i.e. RR-7288 and can be accessible at: http://hal.archives-ouvertes.fr/inria-00482910/en/.This paper introduces a new channel selection strategy for reliable contention-aware data dissemination in multi-hop cognitive radio network. The key challenge here is to select channels providing a good tradeoff between connectivity and contention. In other words, channels with good opportunities for communication due to (1) low primary radio nodes (PRs) activities, and (2) limited contention of cognitive ratio nodes (CRs) acceding that channel, have to be selected. Thus, by dynamically exploring residual resources on channels and by monitoring the number of CRs on a particular channel, SURF allows building a connected network with limited contention where reliable communication can take place. Through simulations, we study the performance of SURF when compared with three other related approaches. Simulation results confirm that our approach is effective in selecting the best channels for efficient and reliable multi-hop data dissemination

Interaction Between Hidden Node Collisions and Congestions in Multihop Wireless Ad-hoc Networks

In this work, we study the performance of the IEEE 802.11 MAC protocol and its impact on the transport layer performance in multihop wireless ad-hoc networks. We focus on the hidden node problem that effects heavily the end-to-end delay and the packet loss probability. Through a mathematical analysis, we compute the packet loss probability as a function of the load. We develop a simplified model of a multihop wireless network and we use it to analyze the interaction between collision and congestion. We find that reducing the size of the MAC output queue can increase the applications throughput. This is done by setting the adequate buffer size that makes congestions and collisions operate in the same region. This will also allow closed or open-loop control protocols such as TCP to react correctly to losses caused by collisions as well as losses caused by buffer overflow. Simulation results with TCP traffic corroborate our theoretical analysis

Improving end to end throughput in wireless mutihop network using several control techniques

Nous proposons dans cette thèse trois nouvelles techniques de contrôle spécialement développées pour améliorer le débit observé par un utilisateur final dans un réseau sans fil multi-sauts. Nous présentons d abord un modèle mathématique qui permet d évaluer les pertes dues au terminal caché. Ce modèle est ensuite exploité pour présenter une solution au niveau de la couche MAC permettant d améliorer le débit des connexions TCP. La deuxième technique tente d exploiter les propriétés de diffusion du canal radio. En effet, HbH, utilise le fait que chaque transmission sans fil peut être entendue par les noeuds à proximité, pour détecter la panne d un noeud voisin. Avec HbH, chaque noeud et après la transmission d un message procède à une écoute du canal afin de savoir si son voisin a retransmis le paquet avant que le premier ne prenne la décision de le jeter. HbH peut être utilisé pour détecter la disparition de noeuds voisins due à la mobilité par exemple. Finalement, nous nous intéressons aux réseaux radios cognitifs. Dans ce nouveau, des problèmes de base restent encore non résolus. Une première technique de contrôle envisageable consiste à présenter des mécanismes de routage capables d établir un chemin de bout en bout tout en tenant compte de l instabilité de ces réseaux. Pour ces raisons, nous proposons MPP, un algorithme de routage spécialement conçu pour les réseaux radios cognitifs multi-sauts. Notre protocole établit un chemin et un ensemble de canaux radios à utiliser entre un nœud source et une destination en se basant sur des calculs probabilistes qui prennent en compte l emplacement et l activité des noeuds primaires plus prioritaires sur les canaux en questions.PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Mathématiques rech (751052111) / SudocSudocFranceF