Results 1 
9 of
9
Opportunitybased topology control in wireless sensor networks
 in ICDCS
, 2008
"... Topology control is an effective method to improve the energy efficiency of wireless sensor networks (WSNs). Traditional approaches are based on the assumption that a pair of nodes is either “connected ” or “disconnected”. These approaches are called connectivitybased topology control. In real envi ..."
Abstract

Cited by 91 (15 self)
 Add to MetaCart
Topology control is an effective method to improve the energy efficiency of wireless sensor networks (WSNs). Traditional approaches are based on the assumption that a pair of nodes is either “connected ” or “disconnected”. These approaches are called connectivitybased topology control. In real environments however, there are many intermittently connected wireless links called lossy links. Taking a succeeded lossy link as an advantage, we are able to construct more energyefficient topologies. Towards this end, we propose a novel opportunitybased topology control. We show that opportunitybased topology control is a problem of NPhard. To address this problem in a practical way, we design a fully distributed algorithm called CONREAP based on reliability theory. We prove that CONREAP has a guaranteed performance. The worst running time is O(E) where E is the link set of the original topology, and the space requirement for individual nodes is O(d) where d is the node degree. To evaluate the performance of CONREAP, we design and implement a prototype system consisting of 50 Berkeley Mica2 motes. We also conducted comprehensive simulations. Experimental results show that compared with the connectivitybased topology control algorithms, CONREAP can improve the energy efficiency of a network up to 6 times. 1
Distributed File Allocation with Consistency Constraints
 in Proceedings of the International Conference on Distributed Computing Systems
, 1992
"... We consider the resource allocation problem in distributed computing systems that have strict mutual consistency requirements. Our model incorporates the behavior of consistency control algorithms, which ensure that mutual consistency of replicated data is preserved even when communication links of ..."
Abstract

Cited by 12 (1 self)
 Add to MetaCart
We consider the resource allocation problem in distributed computing systems that have strict mutual consistency requirements. Our model incorporates the behavior of consistency control algorithms, which ensure that mutual consistency of replicated data is preserved even when communication links of the computer network and/or computers on which the files reside fail. The problem of resource allocation in these networks is significant in terms of the efficiency of operations and the reliability of the network. The constrained resource allocation problem is formulated as a mixed nonlinear integer program. An efficient algorithm is proposed to solve this problem. The performance of the algorithm is evaluated in terms of the algorithm's accuracy, efficiency and execution times, using a representative problem set. 1 Introduction Consider a distributed computing system (DCS) that is made up of a set of sites (nodes) connected through communication links which transmit information from one s...
Uncertainty Bounds for a Monotone Multistate System
 Probability in the Engineering and Informational Sciences
, 1998
"... We consider a monotone multistate system with conditionally independent components given the component reliabilities, and random component reliabilities. Upper and lower bounds are derived for the moments of the random reliability function, extending results for binary systems. The second moment of ..."
Abstract

Cited by 2 (0 self)
 Add to MetaCart
We consider a monotone multistate system with conditionally independent components given the component reliabilities, and random component reliabilities. Upper and lower bounds are derived for the moments of the random reliability function, extending results for binary systems. The second moment of the reliability function is given special attention, as this quantity is used to calculate the standard deviation of the system availability estimate. key words: monotone multistate system
Linking Dominations and Signatures in Network Reliability
, 2002
"... Comparing the reliability of two networks of more than modest size can be a computationally intensive exercise. In this paper, domination theory and the notion of the signature of a network, and their respective roles in calculating the reliability of a network, are briefly reviewed. The computat ..."
Abstract

Cited by 2 (0 self)
 Add to MetaCart
Comparing the reliability of two networks of more than modest size can be a computationally intensive exercise. In this paper, domination theory and the notion of the signature of a network, and their respective roles in calculating the reliability of a network, are briefly reviewed. The computational advantages of the former, and the interpretive richness of the latter, beg the question: how are the two related? The exact functional relationship between the signature vector and the vector of signed dominations is obtained. A detailed example is given in which the connection between these two concepts is usefully exploited.
Reliability Analysis of Replicated AndOr Graphs
 Networks
, 1997
"... A computation task running in distributed systems can be represented as a directed graph H(V;E) whose vertices and edges may fail with known probabilities. In this paper, we introduce a reliability measure, called distributed task reliability, to model the reliability of such computation tasks. The ..."
Abstract

Cited by 1 (1 self)
 Add to MetaCart
A computation task running in distributed systems can be represented as a directed graph H(V;E) whose vertices and edges may fail with known probabilities. In this paper, we introduce a reliability measure, called distributed task reliability, to model the reliability of such computation tasks. The distributed task reliability is defined to be the probability that the task can be successfully executed. Due to the AndFork/AndJoin constraint, the traditional network reliability problem is a special case of the distributed task reliability problem, where the former is known to be NP  hard in general graphs. For twoterminal AndOr SeriesParallel (AOSP) graphs, the distributed task reliability can be computed in polynomial time. We consider a graph H k ( V ; E), named kReplicated AndOr SeriesParallel (RAOSP) graph, which is obtained from an AOSP graph H(V;E) by adding (k \Gamma 1) replications to each vertex and adding proper edges between two vertices. It can be shown that th...
A Generalized Probabilistic Topology Control for Wireless Sensor Networks
"... Abstract—Topology control is an effective method to improve energyefficiency and increase the capacity in Wireless Sensor Networks (WSNs). It reduces the transmitting power of network nodes while the key network connectivity is preserved. In traditional approaches, networks are modeled using a dete ..."
Abstract

Cited by 1 (0 self)
 Add to MetaCart
Abstract—Topology control is an effective method to improve energyefficiency and increase the capacity in Wireless Sensor Networks (WSNs). It reduces the transmitting power of network nodes while the key network connectivity is preserved. In traditional approaches, networks are modeled using a deterministic approach that assumes a pair of nodes are either connected or disconnected. In practice, however, most wireless links are lossy links that provide probabilistic connectivity only. To fully characterize WSNs with lossy links, we propose a novel probabilistic network model. Under this model, we meter the network quality using network reachability defined as the minimal of the upper limit of the endtoend delivery ratio between any pair of nodes in the network.We attempt to find a minimal transmitting power for each node while the network reachability is above a given applicationspecified threshold, called probabilistic topology control (PTC). We prove that PTC is NPhard and propose a fully distributed algorithm called BRASP. We prove that BRASP has the guaranteed performance. Two rules that must be followed by any algorithm for PTC have been identified. BRASP has the promising features on the overhead. The communication overhead is O(E  + V ), the worst running time is O(E), and the space requirement is O(1) where E is the set of links and V is the set of nodes. We conduct both simulations and prototype implementations based an 18TelosBnode testbed. The experimental results show that the network energyefficiency can be improved by up to 250%. The average node degree is reduced by 50 % which will lead to a great benefit for the network capacity.
Domination Invariant of a Diameter
"... Let G = (V, E) be a digraph with a distinguished set of terminal vertices K V and a vertex s K. We define the s, Kdiameter of G as the maximum distance between s and any of vertices of K. If the arcs fail randomly and independently with known probabilities (vertices are always operational), ..."
Abstract
 Add to MetaCart
Let G = (V, E) be a digraph with a distinguished set of terminal vertices K V and a vertex s K. We define the s, Kdiameter of G as the maximum distance between s and any of vertices of K. If the arcs fail randomly and independently with known probabilities (vertices are always operational), the Diameterconstrained s, Kterminal reliability of G, R s,K (G, D), is defined as the probability that surviving arcs span a subgraph whose s, Kdiameter does not exceed D.
”Evaluation and optimization of innovative production systems of goods and services” DYNAMIC MODEL TO THE RELIABILITY EVALUATION OF THE TELECOMMUNICATION NETWORK
"... ABSTRACT: In this paper, we defined the dynamic model to treat the problem of evaluation of reliability measures of a telecommunication network. We used two approaches, the first is based on the factoring method when the second is based on discrete events simulation techniques. We give some numerica ..."
Abstract
 Add to MetaCart
ABSTRACT: In this paper, we defined the dynamic model to treat the problem of evaluation of reliability measures of a telecommunication network. We used two approaches, the first is based on the factoring method when the second is based on discrete events simulation techniques. We give some numerical results on the telecommunication network of Bejaia town.
A DiameterConstrained Network Reliability model to determine the Probability that a Communication Network meets Delay Constraints
"... Abstract: In this paper we provide a summary of results and applications pertaining a Diameterconstrained Network reliability model. Classical network reliability models measure the probability that there exist endtoend paths between network nodes, not taking into account the length of these path ..."
Abstract
 Add to MetaCart
Abstract: In this paper we provide a summary of results and applications pertaining a Diameterconstrained Network reliability model. Classical network reliability models measure the probability that there exist endtoend paths between network nodes, not taking into account the length of these paths. For many applications this is inadequate because the connection will only be established or attain the required quality if the distance between the connecting nodes does not exceed a given value. The Diameterconstrained reliability of a network (DCR) introduced recently considers not only the underlying topology, but also imposes a bound on the diameter, which is the maximum distance between the nodes of the network. We present a synopsis of the known results and applications of the DCR for networks that can either be modeled by directed as well as undirected graphs. Moreover important combinatorial and computational properties of this reliability measure are discussed. As the DCR subsumes the classical reliability measure (i.e., where no distance constraints are imposed on the paths connecting the nodes), as a byproduct we prove wellknown classical results.