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Distributed topology control for power efficient operation in multihop wireless ad hoc networks
, 2001
"... Abstract — The topology of wireless multihop ad hoc networks can be controlled by varying the transmission power of each node. We propose a simple distributed algorithm where each node makes local decisions about its transmission power and these local decisions collectively guarantee global connecti ..."
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Cited by 313 (20 self)
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Abstract — The topology of wireless multihop ad hoc networks can be controlled by varying the transmission power of each node. We propose a simple distributed algorithm where each node makes local decisions about its transmission power and these local decisions collectively guarantee global connectivity. Specifically, based on the directional information, a node grows it transmission power until it finds a neighbor node in every direction. The resulting network topology increases network lifetime by reducing transmission power and reduces traffic interference by having low node degrees. Moreover, we show that the routes in the multihop network are efficient in power consumption. We give an approximation scheme in which the power consumption of each route can be made arbitrarily close to the optimal by carefully choosing the parameters. Simulation results demonstrate significant performance improvements. I.
Analysis of a conebased distributed topology control algorithm for wireless multihop networks
 In ACM Symposium on Principle of Distributed Computing (PODC
, 2001
"... bahl~microsoft, corn ymwang~microsoft, corn rogerwa~microsoft, corn The topology of a wireless multihop network can be controlled by varying the transmission power at each node. In this paper, we give a detailed analysis of a conebased distributed topology control algorithm. This algorithm, intr ..."
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Cited by 134 (9 self)
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bahl~microsoft, corn ymwang~microsoft, corn rogerwa~microsoft, corn The topology of a wireless multihop network can be controlled by varying the transmission power at each node. In this paper, we give a detailed analysis of a conebased distributed topology control algorithm. This algorithm, introduced in [16], does not assume that nodes have GPS information available; rather it depends only on directional information. Roughly speaking, the basic idea of the algorithm is that a node u transmits with the minimum power P~,,a required to ensure that in every cone of degree a around u, there is some node that u can reach with power Pma We show that taking a = 57r/6 is a necessary and sufficient condition to guarantee that network connectivity is preserved. More precisely, if there is a path from a to t when every node communicates at maximum power then, if a < _ 5~r/6, there is still a path in the smallest symmetric graph Ga containing all edges (u, v) such that u can communicate with v using power p~,a. On the other hand, if ~> 51r/6, connectivity is not necessarily preserved. We also propose a set of optimizations that further reduce power consumption and prove that they retain network connectivity. Dynamic reconfiguration in the presence of failures and mobility is also discussed. Simulation results are presented to demonstrate the effectiveness of the algorithm and the optimizations. 1.
Overview of Radiolocation in CDMA Cellular Systems
 IEEE Communications Magazine
, 1998
"... Applications for the location of subscribers of wireless services continue to expand. Consequently, location techniques for wireless technologies are being investigated. With codedivision multiple access (CDMA) being deployed by a variety of cellular and PCS providers, developing an approach for lo ..."
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Cited by 90 (0 self)
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Applications for the location of subscribers of wireless services continue to expand. Consequently, location techniques for wireless technologies are being investigated. With codedivision multiple access (CDMA) being deployed by a variety of cellular and PCS providers, developing an approach for location in CDMA networks is imperative. This article discusses the applications of location technology, the methods available for its implementation in CDMA networks, and the problems that are encountered when using CDMA networks for positioning. ireless location has received considerable attention over the past few years. A recent Report and Order issued by the U.S. Federal Communications Commission (FCC) in July 1996 requires that all wireless service providers, including cellular, broadband PCS, and widearea SMR licensees, provide location information to Emergency 911 (E911) public safety services [1]. These
Faulttolerant and 3Dimensional Distributed Topology Control Algorithms in Wireless Multihop Networks
 in Proceedings of the 11th IEEE International Conference on Computer Communications and Networks (ICCCN
, 2002
"... We can control the topology of a multihop wireless network by varying the transmission power at each node. The lifetime of such networks depends on battery power at each node. This paper presents a distributed faulttolerant topology control algorithm for minimum energy consumption in these net ..."
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Cited by 63 (10 self)
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We can control the topology of a multihop wireless network by varying the transmission power at each node. The lifetime of such networks depends on battery power at each node. This paper presents a distributed faulttolerant topology control algorithm for minimum energy consumption in these networks. More precisely, we present algorithms which preserve the connectivity of a network upon failing of, at most, k nodes (k is constant) and simultaneously minimize the transmission power at each node to some extent. In addition, we present simulations to support the effectiveness of our algorithm. We also demonstrate some optimizations to further minimize the power at each node. Finally, we show how our algorithms can be extended to 3dimensions.
Topology Control for Ad hoc Networks with Directional Antennas
 Proc. IEEE Int. Conference on Computer Communications and Networks
, 2002
"... Topology control for ad hoc networks aims to increase effective network capacity and conserve energy. Most proposed algorithms assume the usage of isotropic antennas and thus only adjust the transmission power of each node. We propose a distributed topology control mechanism for ad hoc networks with ..."
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Cited by 37 (1 self)
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Topology control for ad hoc networks aims to increase effective network capacity and conserve energy. Most proposed algorithms assume the usage of isotropic antennas and thus only adjust the transmission power of each node. We propose a distributed topology control mechanism for ad hoc networks with directional antennas that adjusts antenna pattern (direction(s)) in addition to transmission power. Simulation studies have been conducted to demonstrate the effectiveness of the approach, as well as to investigate its benefits and impacts on application layer performance.
Computing 2Hop Neighborhoods in Ad Hoc Wireless Networks
 In ADHOCNOW’03
, 2003
"... We present efficient distributed algorithms for computing 2hop neighborhoods in Ad Hoc Wireless Networks. The knowledge of the 2hop neighborhood is assumed in many protocols and algorithms for routing, clustering, and distributed channel assignment, but no efficient distributed algorithms for comp ..."
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Cited by 36 (0 self)
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We present efficient distributed algorithms for computing 2hop neighborhoods in Ad Hoc Wireless Networks. The knowledge of the 2hop neighborhood is assumed in many protocols and algorithms for routing, clustering, and distributed channel assignment, but no efficient distributed algorithms for computing the 2hop neighborhoods were previously published. The problem is nontrivial,...
A ConeBased Distributed TopologyControl Algorithm for Wireless MultiHop Networks
 IEEE/ACM Transactions on Networking
, 2002
"... The topology of a wireless multihop network can be controlled by varying the transmission power at each node. In this paper, we give a detailed analysis of a conebased distributed topology control algorithm. This algorithm does not assume that nodes have GPS information available; rather it dep ..."
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Cited by 36 (1 self)
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The topology of a wireless multihop network can be controlled by varying the transmission power at each node. In this paper, we give a detailed analysis of a conebased distributed topology control algorithm. This algorithm does not assume that nodes have GPS information available; rather it depends only on directional information. Roughly speaking, the basic idea of the algorithm is that a node u transmits with the minimum power p u,# required to ensure that in every cone of degree # around u, there is some node that u can reach with power p u,# . We show that taking # = 5#/6 is a necessary and su#cient condition to guarantee that network connectivity is preserved. More precisely, if there is a path from s to t when every node communicates at maximum power then, if # 5#/6, there is still a path in the smallest symmetric graph G # containing all edges (u, v) such that u can communicate with v using power p u,# . On the other hand, if # > 5#/6, # This is a revised and extended version of "Analysis of a conebased topology control algorithm for wireless multihop networks", which appeared in Proceedings of ACM Principles of Distributed Computing (PODC), 2001, and includes results from "Distributed topology control for power e#cient operation in multihop wireless ad hoc networks", by R. Wattenhofer, L. Li, P. Bahl, and Y. M. Wang, which appeared in Proceedings of IEEE INFOCOM, 2001.
Networkbased wireless location
 IEEE Signal Process. Mag
, 2005
"... [Challenges faced in developing techniques for accurate wireless location information] Wireless location refers to the geographic coordinates of a mobile subscriber in cellular or wireless local area network (WLAN) environments. Wireless location finding has emerged as an essential public safety fea ..."
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Cited by 32 (1 self)
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[Challenges faced in developing techniques for accurate wireless location information] Wireless location refers to the geographic coordinates of a mobile subscriber in cellular or wireless local area network (WLAN) environments. Wireless location finding has emerged as an essential public safety feature of cellular systems in response to an order issued by the Federal Communications Commission (FCC) in 1996. The order mandated all wireless service providers to deliver accurate location information of an emergency 911 (E911) caller to public safety answering points (PSAPs). The FCC mandate aims to solve a serious public safety problem caused by the fact that, at present, a large proportion of all 911 calls originate from mobile phones, the location of which cannot be determined with existing technology. However, many difficulties intrinsic to the wireless environment make meeting the FCC objective challenging; these challenges include channel fading, low signaltonoise ratios (SNRs), multiuser interference, and multipath conditions. In addition to emergency services, there are many other applications for wireless location technology, including monitoring and tracking for security reasons, location sensitive
Fast distributed algorithm for convergecast in ad hoc geometric radio networks
 Proc. 2nd Int. Conf. on Wireless on Demand Network Systems and Service (WONS
, 2005
"... Abstract — Wireless ad hoc radio networks have gained a lot of attention in recent years. We consider geometric networks, where nodes are located in a euclidean plane. We assume that each node has a variable transmission range and can learn the distance to the closest neighbor. We also assume that n ..."
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Cited by 29 (0 self)
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Abstract — Wireless ad hoc radio networks have gained a lot of attention in recent years. We consider geometric networks, where nodes are located in a euclidean plane. We assume that each node has a variable transmission range and can learn the distance to the closest neighbor. We also assume that nodes have a special collision detection (CD) capability so that a transmitting node can detect a collision within its transmission range. We study the basic communication problem of collecting data from all nodes called convergecast. Recently, there appeared many new applications such as realtime multimedia, battlefield communications and rescue operations that impose stringent delay requirements on the convergecast time. We measure the latency of convergecast, that is the number of time steps needed to collect the data in any nnode network. We propose a very simple randomized distributed algorithm that has the expected running time O(log n). We also show that this bound is tight and any algorithm needs Ω(log n) time steps while performing convergecast in an arbitrary network. One of the most important problems in wireless ad hoc networks is to minimize the energy consumption, which maximizes the network lifetime. We study the tradeoff between the energy and the latency of convergecast. We show that our algorithm consumes at most O(n log n) times the minimum energy. We also demonstrate that for a line topology the minimum energy convergecast takes n − 1 time steps while any algorithm performing convergecast within O(log n) time steps requires Ω(n) times the minimum energy.
On flow marking attacks in wireless anonymous communication networks
 In Proc. of IEEE Inter. Conf. on Distributed Computing Systems (ICDCS
, 2005
"... This paper studies the degradation of anonymity in a flowbased wireless mix network under flow marking attacks, in which an adversary embeds a recognizable pattern of marks into wireless traffic flows by electromagnetic interference. We find that traditional mix technologies are not effective in de ..."
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Cited by 21 (10 self)
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This paper studies the degradation of anonymity in a flowbased wireless mix network under flow marking attacks, in which an adversary embeds a recognizable pattern of marks into wireless traffic flows by electromagnetic interference. We find that traditional mix technologies are not effective in defeating flow marking attacks, and it may take an adversary only a few seconds to recognize the communication relationship between hosts by tracking such artificial marks. Flow marking attacks utilize frequency domain analytical techniques and convert time domain marks into invariant feature frequencies. To counter flow marking attacks, we propose a new countermeasure based on digital filtering technology, and show that this filterbased countermeasure can effectively defend a wireless mix network from flow marking attacks. 1