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Connectivity in AdHoc and Hybrid Networks
 IN PROC. IEEE INFOCOM
, 2002
"... We consider a largescale wireless network, but with a low density of nodes per unit area. Interferences are then less critical, contrary to connectivity. This paper studies the latter property for both a purely adhoc network and a hybrid network, where fixed base stations can be reached in multipl ..."
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Cited by 160 (6 self)
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We consider a largescale wireless network, but with a low density of nodes per unit area. Interferences are then less critical, contrary to connectivity. This paper studies the latter property for both a purely adhoc network and a hybrid network, where fixed base stations can be reached in multiple hops. We assume here that power constraints are modeled by a maximal distance above which two nodes are not (directly) connected. We find that
An Epidemic Model for Information Diffusion in MANETs
 In Proceedings of the 5th ACM international workshop on
, 2002
"... Choosing appropriate information dissemination strategies is crucial in mobile ad hoc networks (MANET) due to the frequent topology changes. Floodingbased approaches like diffusion have a strong similarity with epidemic spreading of diseases. Applying epidemiological models to information diffusion ..."
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Cited by 48 (2 self)
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Choosing appropriate information dissemination strategies is crucial in mobile ad hoc networks (MANET) due to the frequent topology changes. Floodingbased approaches like diffusion have a strong similarity with epidemic spreading of diseases. Applying epidemiological models to information diffusion allows the evaluation of such strategies depending on the MANET characteristics, e.g. the node density. In order to choose appropriate strategies at run time, the model should be easily evaluated.
Phase Transition Phenomena in Wireless Ad Hoc Networks
, 2001
"... There are many contexts in distributed wireless networks where there is a critical threshold, corresponding to a minimum amount of the communication effort or power expenditure by individual nodes, above which a desirable global property exists with high probability. When this individual node ef ..."
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Cited by 41 (0 self)
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There are many contexts in distributed wireless networks where there is a critical threshold, corresponding to a minimum amount of the communication effort or power expenditure by individual nodes, above which a desirable global property exists with high probability. When this individual node effort is below the threshold the desired global property exists with a low probability. This "phase transition" is typically seen to become sharper as the number of nodes in the network increases. We discuss in this paper some examples of properties that exhibit such critical behavior: node reachability with probabilistic flooding, adhoc network connectivity, and sensor network coordination. We discuss the connections between these phenomena and the phase transitions that have been shown to arise in random graphs. We argue that a good understanding of these phase transition phenomena can provide useful design principles for engineering distributed wireless networks.
Critical Density Thresholds in Distributed Wireless Networks
 IN COMMUNICATIONS, INFORMATION AND NETWORK SECURITY
, 2002
"... We present experimental and analytical results showing "zeroone" phase transitions for network connectivity, multipath reliability, neighbor count, Hamiltonian cycle formation, multipleclique formation, and probabilistic flooding. These transitions are characterized by critical density thresholds ..."
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Cited by 16 (2 self)
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We present experimental and analytical results showing "zeroone" phase transitions for network connectivity, multipath reliability, neighbor count, Hamiltonian cycle formation, multipleclique formation, and probabilistic flooding. These transitions are characterized by critical density thresholds such that a global property exists with negligible probability on one side of the threshold, and exists with high probability on the other. We discuss the connections between these phase transitions and some known results on random graphs, and indicate their significance for the design of resourceefficient wireless networks.
The impact of power amplifier characteristics on routing in random wireless networks
 in Proc., IEEE Globecom
, 2003
"... Abstract — Power amplifiers for wireless transmission provide a limited radiated power, and their efficiency depends highly on the operating point. We show that power control and routing strategies in multihop wireless networks are strongly affected by these nonideal amplifier characteristics. For ..."
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Cited by 14 (6 self)
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Abstract — Power amplifiers for wireless transmission provide a limited radiated power, and their efficiency depends highly on the operating point. We show that power control and routing strategies in multihop wireless networks are strongly affected by these nonideal amplifier characteristics. For the analysis, we prove that the distances in random networks are governed by a generalized Rayleigh distribution, and we determine the power efficiency of different routing schemes. The main result is that nearestneighbor routing is highly inefficient if the network has to be connected with high probability. I.
Optimal Transmission Radius for Flooding in Large Scale Sensor Networks
 IN 23RD INTERNATIONAL CONFERENCE ON DISTRIBUTED COMPUTING SYSTEMS WORKSHOPS (ICDCSW’03
, 2003
"... One of the principal characteristics of large scale wireless sensor networks is their distributed, multihop nature. Due to ..."
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Cited by 8 (0 self)
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One of the principal characteristics of large scale wireless sensor networks is their distributed, multihop nature. Due to
Power Aware Routing using Power Control in Ad Hoc Networks
"... Abstract — A conventional routing protocol selects a path using the shortest number of hops as a routing metric. It has been proposed that a different routing metric may be useful to achieve energy savings. One such poweraware routing metric is minimizing the aggregate transmit power on a path from ..."
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Cited by 2 (0 self)
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Abstract — A conventional routing protocol selects a path using the shortest number of hops as a routing metric. It has been proposed that a different routing metric may be useful to achieve energy savings. One such poweraware routing metric is minimizing the aggregate transmit power on a path from a source to a destination. This metric has been used along with a simple power control protocol, which uses the maximum transmit power for the transmission of RTS and CTS and the minimum necessary transmit power for the transmission of DATA and ACK. Although this type of power control protocol does not provide spatial reuse it can conserve energy. We will refer to this kind of power control as the BASIClike power control protocol. In this paper we show that a power aware routing, minimizing the total transmit power, with BASIClike power control does not save energy, which contradicts to previous studies in literatures. The reason is simple and intuitive but it has been entirely overlooked. Using the power aware routing metric, the selected paths can be much longer than the shortest path. In other words, there can be more number of hops between a source and a destination. Since BASIClike power control does not provide spatial reuse nodes on a path have to share and compete for the channel bandwidth. Therefore, the throughput achieved between a source and a destination can be lower than that of IEEE 802.11 without power control. Also, we found that the metric leads to lower data bits delivered per unit of transmit energy. We show that using the shortest number of hops in conjunction with BASIClike power control conserves more energy than the power aware routing with BASIClike power control. Index Terms — IEEE 802.11, power control MAC protocol, energy saving, power aware routing, wireless network. I.
Phase Transition Phenomena in Wireless Ad Hoc Networks
, 2001
"... There are many contexts in distributed wireless networks where there is a critical threshold, corresponding to a minimum amount of the communication effort or power expenditure by individual nodes, above which a desirable global property exists with high probability. When this individual node ef ..."
Abstract

Cited by 1 (0 self)
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There are many contexts in distributed wireless networks where there is a critical threshold, corresponding to a minimum amount of the communication effort or power expenditure by individual nodes, above which a desirable global property exists with high probability. When this individual node effort is below the threshold the desired global property exists with a low probability. This "phase transition" is typically seen to become sharper as the number of nodes in the network increases. We discuss in this paper some examples of properties that exhibit such critical behavior: node reachability with probabilistic flooding, adhoc network connectivity, and sensor network coordination. We discuss the connections between these phenomena and the phase transitions that have been shown to arise in random graphs. We argue that a good understanding of these phase transition phenomena can provide useful design principles for engineering distributed wireless networks.
GENERALIZATION OF CRITICAL TRANSMISSION RANGE FOR CONNECTIVITY TO WIRELESS MULTIHOP NETWORK MODELS INCLUDING INTERFERENCE
"... The connectivity of wireless multihop networks has mostly been studied neglecting interference, assuming that all network nodes have a common transmission range within which they can form direct links. Under this assumption, the critical transmission range for connectivity of a given network equals ..."
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The connectivity of wireless multihop networks has mostly been studied neglecting interference, assuming that all network nodes have a common transmission range within which they can form direct links. Under this assumption, the critical transmission range for connectivity of a given network equals the greatest edge length in the Euclidean minimum spanning tree of the network nodes. While the impact of interferences on the percolation phenomena of infinite networks has been studied [1], little is known about the graph connectivity of finite networks under more realistic network models. In this paper, we generalize the critical range for connectivity to two network models presented earlier which are both based on a minimum required signaltonoiseandinterference ratio for successful communication. As these models have more than one free parameters, the critical range generalizes into a boundary in the space of these parameters; we show how to determine this boundary for a given network. The connectivity boundary implies tradeoffs between different parameters dictating network performance. Our results allow studying the connectivity of interferenceslimited networks by simulation and give insight on the sensitivity of connectivity to different network parameters. KEY WORDS ad hoc networks, physical model, connectivity, network performance 1
An Ideal Connectivity for Ad Hoc Systems
"... Abstract: According to the common underlying mathematical model of ad hoc networks introduced, a selective network model is defined to analyze local node connectivity. Based on a system architecture with a predetermined number of independent and simultaneous links of each network node, the differen ..."
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Abstract: According to the common underlying mathematical model of ad hoc networks introduced, a selective network model is defined to analyze local node connectivity. Based on a system architecture with a predetermined number of independent and simultaneous links of each network node, the different optimization degrees of the selection of neighbors are presented. A higher relaying efficiency gives the main opportunity for an ad hoc net to be an essential part of a future networking system. The efficiency of a selective network connectivity is compared to pure range controlled connectivity. KeyWords: Ad hoc network models, Ideal local node connectivity, Optimization degrees of local connectivity. 1