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65
Target Transmission Radius over LMST for EnergyEfficient Broadcast Protocol in Ad Hoc Networks
 In Proceedings of the IEEE International Conference on Communications (ICC’04
, 2004
"... We investigate minimum energy broadcasting problem where mobile nodes have the capability to adjust their transmission range. The power consumption for two nodes at distance is +c, where # # 2 and c is a constant that includes signal processing and minimal reception power. We show that, for ..."
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Cited by 16 (8 self)
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We investigate minimum energy broadcasting problem where mobile nodes have the capability to adjust their transmission range. The power consumption for two nodes at distance is +c, where # # 2 and c is a constant that includes signal processing and minimal reception power. We show that, for c > 0 (which is realistic assumption), it is not optimal to minimize transmission range. Furthermore, we demonstrate that there exists an optimal radius, computed with an hexagonal tiling of the network area, that minimizes the power consumption. For # > 2 and c > 0, the optimal radius is r = ., which is derived theoretically, and confirmed experimentally. We propose also a localized broadcast algorithm TRLBOP which takes this optimal radius into account. This protocol is experimentally shown to be efficient compared to existing localized protocol LBOP and globalized BIP protocol. Most importantly, TRLBOP is shown to have limited energy overhead with respect to BIP for all network densities, which is not the case with LBOP whose overhead explodes for higher densities.
A Unified EnergyEfficient Topology for Unicast and Broadcast
 In ACM MOBICOM
, 2005
"... We propose a novel communication efficient topology control algorithm for each wireless node to select communication neighbors and adjust its transmission power, such that all nodes together selfform a topology that is energy efficient simultaneously for both unicast and broadcast communications. W ..."
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Cited by 12 (3 self)
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We propose a novel communication efficient topology control algorithm for each wireless node to select communication neighbors and adjust its transmission power, such that all nodes together selfform a topology that is energy efficient simultaneously for both unicast and broadcast communications. We prove that the proposed topology is planar, which guarantees packet delivery if a certain localized routing method is used; it is power efficient for unicast – the energy needed to connect any pair of nodes is within a small constant factor of the minimum under a common power attenuation model; it is efficient for broadcast: the energy consumption for broadcasting data on top of it is asymptotically the best compared with structures constructed locally; it has a constant bounded logical degree, which will potentially reduce interference and signal contention. We further prove that the average physical degree of all nodes is bounded by a small constant. To the best of our knowledge, this is the first communicationefficient distributed algorithm to achieve all these properties. Previously, only a centralized algorithm was reported in [3]. Moreover, by assuming that the ID and position of every node can be represented in O(log n) bits for a wireless network of n nodes, our method uses at most 13n messages, where each message is of O(log n) bits. We also show that this structure can be efficiently updated for dynamical network environment. Our theoretical results are corroborated in the simulations.
Variable radii connected sensor cover in sensor networks
 in Proc. of the IEEE International Conference on Sensor and Ad Hoc Communications and Networks (SECON
, 2004
"... Abstract—One of the useful approaches to exploit redundancy in a sensor network is to keep active only a small subset of sensors that are sufficient to cover the region required to be monitored. The set of active sensors should also form a connected communication graph, so that they can autonomously ..."
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Cited by 12 (2 self)
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Abstract—One of the useful approaches to exploit redundancy in a sensor network is to keep active only a small subset of sensors that are sufficient to cover the region required to be monitored. The set of active sensors should also form a connected communication graph, so that they can autonomously respond to application queries and/or tasks. Such a set of active sensor is known as a connected sensor cover, and the problem of selecting a minimum connected sensor cover has been well studied when the transmission radius and sensing radius of each sensor is fixed. In this article, we address the problem of selecting a minimum energycost connected sensor cover, when each sensor node can vary its sensing and transmission radius; larger sensing or transmission radius entails higher energy cost. For the above problem, we design various centralized and distributed algorithms, and compare their performance through extensive experiments. One of the designed centralized algorithms (called CGA) is shown to perform within an O(log n) factor of the optimal solution, where n is the size of the network. We have also designed a localized algorithm based on Voronoi diagrams which is empirically shown to perform very close to CGA, and due to its communicationefficiency results in significantly prolonging the sensor network lifetime. I.
Optimized stateless broadcasting in wireless multihop networks
 In INFOCOM
, 2006
"... Abstract — In this paper we present a simple and stateless ..."
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Cited by 11 (2 self)
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Abstract — In this paper we present a simple and stateless
Low latency broadcast in multiradio multichannel multirate wireless mesh networks
 Third Annual IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks SECON
, 2006
"... Abstract: We address the problem of minimizing the worstcase broadcast delay in multiradio multichannel multirate (MR 2MC) wireless mesh networks (WMN). The problem of ‘efficient ’ broadcast in such networks is especially challenging due to the numerous interrelated decisions that have to be ma ..."
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Cited by 10 (2 self)
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Abstract: We address the problem of minimizing the worstcase broadcast delay in multiradio multichannel multirate (MR 2MC) wireless mesh networks (WMN). The problem of ‘efficient ’ broadcast in such networks is especially challenging due to the numerous interrelated decisions that have to be made. The multirate transmission capability of WMN nodes, interference between wireless transmissions, and the hardness of optimal channel assignment adds complexity to our considered problem. We present four heuristic algorithms to solve the minimum latency broadcast problem for such settings and show that the ‘best ’ performing algorithms usually adapt themselves to the available radio interfaces and channels. We also study the effect of channel assignment on broadcast performance and show that channel assignment can affect the broadcast performance substantially. More importantly, we show that a channel assignment that performs well for unicast does not necessarily perform well for broadcast/multicast. To the best of our knowledge, this work constitutes the first contribution in the area of broadcast routing for MR 2MC WMN. I.
Localized Broadcast Incremental Power Protocol for Wireless Ad Hoc Networks
 DEPARTMENT AT THE UNIVERSITY OF OTTAWA (CANADA
, 2004
"... An efficient broadcast protocol is of prime importance in a wireless ad hoc network. The best known algorithm, BIP (Broadcast Incremental Power), constructs a broadcast tree from a source node and offers very good results in terms of energy savings. Unfortunately, its computation is centralized, as ..."
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Cited by 9 (1 self)
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An efficient broadcast protocol is of prime importance in a wireless ad hoc network. The best known algorithm, BIP (Broadcast Incremental Power), constructs a broadcast tree from a source node and offers very good results in terms of energy savings. Unfortunately, its computation is centralized, as the source node needs to know the entire topology of the network to compute the tree. Many localized protocols have been proposed, but none has ever reached the performances of BIP. In this paper, we propose and analyze a localized broadcasting protocol that makes use of the principles of BIP. In our method, each node is aware of the position of all its neighbors within two hops. The source applies the BIP scheme on the set of its twohops neighbors, and includes in the message the list of its neighbors that need to retransmit, together with the desired transmission radii. Each node that receives the message with the order to relay computes the coverage of its neighborhood based on requested radii and does the same as the source node. Experimental results show that this new protocol has performances very close to other good ones for low densities, and is very energyefficient for higher densities with performances near as good as BIP.
Low latency multimedia broadcast in multirate wireless meshes
 in: Proceedings of the First IEEE Workshop on Wireless Mesh Networks, 2005
"... Abstract — In a multirate wireless network, a node can dynamically adjust its link transmission rate by switching between different modulation schemes. For the current IEEE802.11a/b/g standards, this rate adjustment is limited to unicast traffic only while multicast and broadcast traffic is always ..."
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Cited by 9 (4 self)
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Abstract — In a multirate wireless network, a node can dynamically adjust its link transmission rate by switching between different modulation schemes. For the current IEEE802.11a/b/g standards, this rate adjustment is limited to unicast traffic only while multicast and broadcast traffic is always transmitted at the lowest possible rate. In this paper, we consider a novel type of multirate mesh networks where a node can dynamically adjust its link layer multicast rates to its neighbours. In particular, we consider the problem of realising low latency networkwide broadcast in this type of multirate wireless meshes. We will first show that the multirate broadcast problem is significantly different from the singlerate case. We will then present an algorithm for achieving low latency broadcast in a multirate mesh which exploits both wireless broadcast advantage and the multirate nature of the network. I.
Fault tolerant connected sensor cover with variable sensing and transmission ranges
 in IEEE SECON
, 2005
"... Abstract — Sensor networks are often deployed in a redundant fashion. In order to prolong the network lifetime, it is desired to choose only a subset of sensors to keep active and put the rest to sleep. In order to provide fault tolerance, this small subset of active sensors should also provide some ..."
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Cited by 9 (1 self)
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Abstract — Sensor networks are often deployed in a redundant fashion. In order to prolong the network lifetime, it is desired to choose only a subset of sensors to keep active and put the rest to sleep. In order to provide fault tolerance, this small subset of active sensors should also provide some degree of redundancy. In this paper, we consider the problem of choosing a minimum subset of sensors such that they maintain a required degree of coverage and also form a connected network with a required degree of fault tolerance. In addition, we consider a more general, variable radii sensor model, wherein every sensor can adjust both its sensing and transmission ranges to minimize overall energy consumption in the network. We call this the variable radii k1Connected, k2Cover problem. To address this problem, we propose a distributed and localized Voronoibased algorithm. The approach extends the relative neighborhood graph (RNG) structure to preserve kconnectivity in a graph, and design a distributed technique to inactivate desirable nodes while preserving kconnectivity of the remaining active nodes. We show through extensive simulations that our proposed techniques result in overall energy savings in random sensor networks over a wide range of experimental parameters. I.
A Dominating Sets and Target Radius Based Localized Activity Scheduling and Minimum Energy Broadcast Protocol for Ad Hoc and Sensor Networks
 In Proc. of the Mediterranean Ad Hoc Networking Workshop (MedHocNet 2004
, 2004
"... Several localized broadcasting protocols for ad hoc and sensor networks were proposed recently, with the goal of minimizing the energy consumption, while still guaranteeing a total coverage of the network. Also, several activity scheduling protocols were proposed, which select nodes in a connected d ..."
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Cited by 8 (2 self)
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Several localized broadcasting protocols for ad hoc and sensor networks were proposed recently, with the goal of minimizing the energy consumption, while still guaranteeing a total coverage of the network. Also, several activity scheduling protocols were proposed, which select nodes in a connected dominating set to be active, with the rest of nodes left in sleep mode for energy savings. This article is the first to consider both problems as a single combined one, in which a localized protocol is proposed as a solution. First, each node considers only neighbors whose distance is no greater than the target radius (which depends on the power consumption model used), and neighbors in a localized connected topological structure such as RNG or LMST. Then, a connected dominating set is constructed using this subgraph. Next, nodes not selected for the set are sent to sleep mode (they periodically wake up for sending and receiving messages from associated closest dominating set nodes). Nodes in selected dominating set remain active and apply neighbor elimination based broadcasting (reduced to a subset of dominant neighbors with the help of the RNG or LMST), with transmission range adjusted to their furthest neighbor (in the considered subgraph) not covered by other transmissions. The algorithm has been implemented and compared with a centralized (BIP) and target radius based minimum energy broadcasting (TRLBOP) protocol (which do not place any node to sleep mode). It is shown that our algorithm requires similar amount of energy for broadcasting as TRLBOP, but in addition also has energy savings coming from sleep mode status of significant number of nodes. Moreover, our protocol offers the advantage of a smaller latency, since fewer nodes participate in the broadcast.
Algorithms for Wireless Sensor Network
 International Journal of Distributed Sensor Networks
, 2005
"... This paper reviews some of the recent advances in the development of algorithms for wireless sensor networks. We focus on sensor deployment and coverage, routing and sensor fusion. ..."
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Cited by 8 (1 self)
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This paper reviews some of the recent advances in the development of algorithms for wireless sensor networks. We focus on sensor deployment and coverage, routing and sensor fusion.