Results 1  10
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20
Fast Broadcasting and Gossiping in Radio Networks
, 2000
"... We establish an O(n log² n) upper bound on the time for deterministic distributed broadcasting in multihop radio networks with unknown topology. This nearly matches the known lower bound of n log n). The fastest previously known algorithm for this problem works in time O(n 3=2 ). Using our broa ..."
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Cited by 87 (6 self)
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We establish an O(n log² n) upper bound on the time for deterministic distributed broadcasting in multihop radio networks with unknown topology. This nearly matches the known lower bound of n log n). The fastest previously known algorithm for this problem works in time O(n 3=2 ). Using our broadcasting algorithm, we develop an O(n 3=2 log 2 n) algorithm for gossiping in the same network model.
On Contention Resolution Protocols and Associated Probabilistic Phenomena
 IN PROCEEDINGS OF THE 26TH ANNUAL ACM SYMPOSIUM ON THEORY OF COMPUTING
, 1994
"... ..."
JAMRESISTANT COMMUNICATION WITHOUT SHARED SECRETS THROUGH THE USE OF CONCURRENT CODES
, 2007
"... We consider the problem of establishing jamresistant, wireless, omnidirectional communication channels when there is no initial shared secret. No existing system achieves this. We propose a general algorithm for this problem, the BBC algorithm, and give several instantiations of it. We develop an ..."
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Cited by 16 (9 self)
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We consider the problem of establishing jamresistant, wireless, omnidirectional communication channels when there is no initial shared secret. No existing system achieves this. We propose a general algorithm for this problem, the BBC algorithm, and give several instantiations of it. We develop and analyze this algorithm within the framework of a new type of code, concurrent codes, which are those superimposed codes that allow efficient decoding. Finally, we propose the Universal Concurrent Code algorithm, and prove that it covers all possible concurrent codes, and give connections between its theory and that of monotone Boolean functions.
A randomized algorithm for gossiping in radio networks
 NETWORKS
, 2004
"... We present an O(n log 4 n)time randomized algorithm for gossiping in radio networks with unknown topology. This is the first algorithm for gossiping in this model whose running time is only a polylogarithmic factor away from the optimum. The fastest previously known (deterministic) algorithm for th ..."
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Cited by 15 (2 self)
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We present an O(n log 4 n)time randomized algorithm for gossiping in radio networks with unknown topology. This is the first algorithm for gossiping in this model whose running time is only a polylogarithmic factor away from the optimum. The fastest previously known (deterministic) algorithm for this problem works in time O(n 3/2 log 2 n).
Randomized communication in radio networks
 HANDBOOK OF RANDOMIZED COMPUTING
, 2001
"... A communication network is called a radio network if its nodes exchange messages in the following restricted way. First, a send operation performed by a node delivers copies of the same message to all directly reachable nodes. Secondly, a node can successfully receive an incoming message only if exa ..."
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Cited by 14 (0 self)
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A communication network is called a radio network if its nodes exchange messages in the following restricted way. First, a send operation performed by a node delivers copies of the same message to all directly reachable nodes. Secondly, a node can successfully receive an incoming message only if exactly one of its neighbors sent a message in that step. It is this semantics of how ports at nodes send and receive messages that defines the networks rather than the fact that only radio waves are used as a medium of communication; but if that is the case then just a single frequency is used. We discuss algorithmic aspects of exchanging information in such networks, concentrating on distributed randomized protocols. Specific problems and solutions depend a lot on the topology of the underlying reachability graph and how much the nodes know about it. In singlehop networks each pair of nodes can communicate directly. This kind of networks is also known as the multiple access channel. Popular
Jam resistant communications without shared secrets
 in Proceedings of the 3 rd International Conference on Information Warfare and Security
, 2008
"... Distribution A, Approved for public release, distribution unlimited Abstract. We consider the problem of establishing jamresistant, wireless, omnidirectional communication channels when there is no initial shared secret. No existing system achieves this. We propose a general algorithm for this prob ..."
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Cited by 10 (1 self)
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Distribution A, Approved for public release, distribution unlimited Abstract. We consider the problem of establishing jamresistant, wireless, omnidirectional communication channels when there is no initial shared secret. No existing system achieves this. We propose a general algorithm for this problem, the BBC algorithm, and give several instantiations of it. We develop and analyze this algorithm within the framework of a new type of code, concurrent codes, which are those superimposed codes that allow efficient decoding. Finally, we propose the Universal Concurrent Code algorithm, and prove that it covers all possible concurrent codes, and give connections between its theory and that of monotone Boolean functions.
Fast Distributed Graph Coloring With ... Colors
"... We consider the problem of deterministic distributed coloring of an nvertex graph with maximum degree \Delta, assuming that every vertex knows a priori only its own label and parameters n and \Delta. The aim is to get a fast algorithm using few colors. Linial [9] showed a vertexcoloring algorit ..."
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Cited by 7 (0 self)
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We consider the problem of deterministic distributed coloring of an nvertex graph with maximum degree \Delta, assuming that every vertex knows a priori only its own label and parameters n and \Delta. The aim is to get a fast algorithm using few colors. Linial [9] showed a vertexcoloring algorithm working in time O(log n) and using O(\Delta 2 ) colors. We improve both the time and the number of colors simultaneously by showing an algorithm working in time O(log (n=\Delta)) and using O(\Delta) colors. This is the first known O(\Delta)vertexcoloring distributed algorithm which can work faster than in polylogarithmic time. Our method also gives an edgecoloring algorithm with the number of colors and time as above. On the other hand, it follows from Linial [9] that our time of O(\Delta)coloring cannot be improved in general. 1
Almost optimal explicit selectors
 FCT 2005. LNCS
, 2005
"... We understand selection by intersection as distinguishing a single element of a set by the uniqueness of its occurrence in some other set. More precisely, given two sets A and B, if A ∩ B = {z}, then element z ∈ A is selected by set B. Selectors are such families S of sets B of some domain that allo ..."
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Cited by 4 (0 self)
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We understand selection by intersection as distinguishing a single element of a set by the uniqueness of its occurrence in some other set. More precisely, given two sets A and B, if A ∩ B = {z}, then element z ∈ A is selected by set B. Selectors are such families S of sets B of some domain that allow to select many elements from sufficiently small subsets A of the domain. Selectors are used in communication protocols for the multipleaccess channel, in implementations of distributedcomputing primitives in radio networks, and in algorithms for group testing. We give new explicit (n, k, r)selectors of size O(min [ k n, 2 k−r+1 polylog n]), for any parameters r ≤ k ≤ n. We establish a lower bound Ω(min [ k n, 2 k−r+1 · log(n/k)) on the length log(k/(k−r+1)) of (n, k, r)selectors, which demonstrates that our construction is within a polylog n factor close to optimal. The new selectors are applied to develop explicit implementations of selection resolution on the multipleaccess channel, gossiping in radio networks and an algorithm for group testing with inhibitors.
Performing Work in Broadcast Networks
, 2001
"... We consider the problem of how to schedule t similar and independent tasks to be performed in a synchronous distributed system of p stations communicating via multipleaccess channels. Stations are prone to crashes whose patterns of occurrence are specified by adversarial models. Work, defined as th ..."
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Cited by 3 (0 self)
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We consider the problem of how to schedule t similar and independent tasks to be performed in a synchronous distributed system of p stations communicating via multipleaccess channels. Stations are prone to crashes whose patterns of occurrence are specified by adversarial models. Work, defined as the number of the available processor steps, is the complexity measure. We consider only reliable algorithms that perform all the tasks as long as at least one station remains operational. It is shown that every reliable algorithm has to perform work Ω(t + p √ t) even when no failures occur. An optimal deterministic algorithm for the channel with collision detection is developed, which performs work O(t + p √ t). Another algorithm, for the channel without collision detection, performs work O(t + p √ t + p · min{f, t}), where f < p is the number of failures. This algorithm is proved to be optimal, provided that the adversary is restricted in failing no more than f stations. Finally, we consider the question if randomization helps against weaker adversaries for the channel without collision detection. A randomized algorithm is developed which performs the expected minimum amount O(t + p √ t) of work, provided that the adversary may fail a constant fraction of stations and it has to select failureprone stations prior to the start of an execution of the algorithm.
Deterministic Communication in the Weak Sensor Model
"... Abstract. In Sensor Networks, the lack of topology information and the availability of only one communication channel has led research work to the use of randomization to deal with collision of transmissions. However, the scarcest resource in this setting is the energy supply, and radio communicatio ..."
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Cited by 3 (3 self)
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Abstract. In Sensor Networks, the lack of topology information and the availability of only one communication channel has led research work to the use of randomization to deal with collision of transmissions. However, the scarcest resource in this setting is the energy supply, and radio communication dominates the sensor node energy consumption. Hence, redundant trials of transmission as used in randomized protocols may be countereffective. Additionally, most of the research work in Sensor Networks is either heuristic or includes unreallistic assumptions. Hence, provable results for many basic problems still remain to be given. In this paper, we study upper and lower bounds for deterministic communication primitives under the harsh constraints of sensor nodes. 1