897 research outputs found

    Clustering algorithm in initialization of multi-hop wireless sensor networks

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    In most application scenarios of wireless sensor networks (WSN), sensor nodes are usually deployed randomly and do not have any knowledge about the network environment or even their ID's at the initial stage of their operations. In this paper, we address the clustering problems with a newly deployed multi-hop WSN where most existing clustering algorithms can hardly be used due to the absence of MAC link connections among the nodes. We propose an effective clustering algorithm based on a random contention model without the prior knowledge of the network and the ID's of nodes. Computer simulations have been used to show the effectiveness of the algorithm with a relatively low complexity if compared with existing schemes

    Modelling Trust In Wireless Sensor Networks from the Sensor Reliability Prospective

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    This paper surveys the state of the art trust-based systems in Wireless Sensor Networks (WSN); it highlights the difference between Mobile ad hoc networks (MANET) and WSN and based on this observed difference (monitoring events and reporting data) a new trust model is introduced, which takes sensor reliability as a component of trust. A new definition of trust is created based on the newly introduced component of trust (sensor data) and an extension of node misbehaviour classification is also presented based on this new component of trust

    Local Approximation Schemes for Ad Hoc and Sensor Networks

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    We present two local approaches that yield polynomial-time approximation schemes (PTAS) for the Maximum Independent Set and Minimum Dominating Set problem in unit disk graphs. The algorithms run locally in each node and compute a (1+ε)-approximation to the problems at hand for any given ε > 0. The time complexity of both algorithms is O(TMIS + log*! n/εO(1)), where TMIS is the time required to compute a maximal independent set in the graph, and n denotes the number of nodes. We then extend these results to a more general class of graphs in which the maximum number of pair-wise independent nodes in every r-neighborhood is at most polynomial in r. Such graphs of polynomially bounded growth are introduced as a more realistic model for wireless networks and they generalize existing models, such as unit disk graphs or coverage area graphs

    Optimal Initialization and Gossiping Algorithms for Random Radio Networks

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    The initialization problem, also known as naming, consists to give a unique identifier ranging from 11 to nn to a set of nn indistinguishable nodes in a given network. We consider a network where nn nodes (processors) are randomly deployed in a square (resp. cube) XX. We assume that the time is slotted and the network is synchronous, two nodes are able to communicate if they are within distance at most of rr of each other (rr is the transmitting/receiving range). Moreover, if two or more neighbors of a processor uu transmit concurrently at the same time slot, then uu would not receive either messages. We suppose also that the anonymous nodes know neither the topology of the network nor the number of nodes in the network. Under this extremal scenario, we first show how the transmitting range of the deployed processors affects the typical characteristics of the network. Then, by allowing the nodes to transmit at various ranges we design sub-linear randomized initialization protocols~: In the two, resp. three, dimensional case, our randomized initialization algorithms run in O(n1/2logn1/2)O(n^{1/2} \log{n}^{1/2}), resp. O(n1/3logn2/3)O(n^{1/3} \log{n}^{2/3}), time slots. These latter protocols are based upon an optimal gossiping algorithm which is of independent interest

    Secure Group Association Management in Heterogeneous Distributed Sensor Networks

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    A Heterogeneous Distributed Sensor Network (HDSN) is a type of distributed sensor network where sensors with different functional types participate at the same time. In this network model, the sensors are associated with different deployment groups but they cooperate with each other within and out of their respective groups. The heterogeneity of HDSN refers to the functional heterogeneity of the sensors participating in the network unlike the heterogeneity considered (e.g., considering transmission range, energy level, computation ability, sensing range) for traditional heterogeneous sensor networks. Taking this model into account, we propose a secure group association authentication mechanism using one-way accumulator which ensures that; before collaborating for a particular task, any pair of nodes in the same deployment group can verify the legitimacy of group association of each other. Secure addition and deletion of sensors are also supported in this approach. In addition, a policy-based sensor addition procedure is also suggested. For secure handling of disconnected node of a group, we use an efficient pairwise key derivation scheme. Side by side proposing our mechanisms, we also discuss the characteristics of HDSN, its scopes, applicability, challenges, and future. The efficiency of our management approach is demonstrated with performance evaluation and analysis

    Random Geometric Graphs and the Initialization Problem for Wireless Networks

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    32 pages. Tutorial invitéInternational audienceThe initialization problem, also known as naming, assigns one unique identifier (ranging from 1 to nn) to a set of n indistinguishable nodes (stations or processors) in a given wireless network NN. NN is composed of nn nodes randomly deployed within a square (or a cube) XX. We assume the time to be slotted and NN to be synchronous; two nodes are able to communicate if they are within a distance at most rr of each other (rr is the transmitting/receiving range). Moreover, if two or more neighbors of a processor uu transmit concurrently at the same round, uu does not receive either messages. After the analysis of various critical transmitting/sensing ranges for connectivity and coverage of randomly deployed sensor networks, we design sub-linear randomized initialization and gossip algorithms achieving O(n1/2log(n)1/2)O(n^1/2 \log(n)^1/2) and O(n1/3log(n)2/3)roundsinthetwodimensionalandthethreedimensionalcases,respectively.Next,weproposeenergyefficientinitializationandgossipalgorithmsrunninginO(n^1/3 \log(n)^2/3) rounds in the two-dimensional and the three-dimensional cases, respectively. Next, we propose energy-efficient initialization and gossip algorithms running in O(n^3/4 \log (n)^1/4)rounds,withnostationbeingawakeformorethanO(n1/4log(n)3/4) rounds, with no station being awake for more than O(n^1/4 \log (n)^3/4) rounds

    An efficient approach of secure group association management in densely deployed heterogeneous distributed sensor network

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    A heterogeneous distributed sensor network (HDSN) is a type of distributed sensor network where sensors with different deployment groups and different functional types participate at the same time. In other words, the sensors are divided into different deployment groups according to different types of data transmissions, but they cooperate with each other within and out of their respective groups. However, in traditional heterogeneous sensor networks, the classification is based on transmission range, energy level, computation ability, and sensing range. Taking this model into account, we propose a secure group association authentication mechanism using one-way accumulator which ensures that: before collaborating for a particular task, any pair of nodes in the same deployment group can verify the legitimacy of group association of each other. Secure addition and deletion of sensors are also supported in this approach. In addition, a policy-based sensor addition procedure is also suggested. For secure handling of disconnected nodes of a group, we use an efficient pairwise key derivation scheme to resist any adversary’s attempt. Along with proposing our mechanism, we also discuss the characteristics of HDSN, its scopes, applicability, future, and challenges. The efficiency of our security management approach is also demonstrated with performance evaluation and analysis

    Enabling reliable and power efficient real-time multimedia delivery over wireless sensor networks

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    There is an increasing need to run real-time multimedia applications, e.g. battle field and border surveillance, over Wireless Sensor Networks (WSNs). In WSNs, packet delivery exhibits high packet loss rate due to congestion, wireless channel high bit error rate, route failure, signal attenuation, etc... Flooding conventional packets over all sensors redundantly provides reliable delivery. However, flooding real-time multimedia packets is energy inefficient for power limited sensors and causes severe contentions affecting reliable delivery. We propose the Flooding Zone Initialization Protocol (FZIP) to enhance reliability and reduce power consumption of real-time multimedia flooding in WSNs. FZIP is a setup protocol which constrains flooding within a small subset of intermediate nodes called Flooding Zone (FZ). Also, we propose the Flooding Zone Control Protocol (FZCP) which monitors the session quality and dynamically changes the FZ size to adapt to current network state, thus providing a tradeoff of good quality and less power consumption
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