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370
Gossipbased ad hoc routing
, 2002
"... Abstract—Many ad hoc routing protocols are based on some variant of flooding. Despite various optimizations, many routing messa ges are propagated unnecessarily. We propose a gossipingbased approa ch, where each node forwards a message with some probability, to reduce the ov erhead of the routing p ..."
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Cited by 371 (4 self)
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Abstract—Many ad hoc routing protocols are based on some variant of flooding. Despite various optimizations, many routing messa ges are propagated unnecessarily. We propose a gossipingbased approa ch, where each node forwards a message with some probability, to reduce the ov erhead of the routing protocols. Gossiping exhibits bimodal behavio r in sufficiently large networks: in some executions, the gossip dies out quic kly and hardly any node gets the message; in the remaining executions, a sub stantial fraction of the nodes gets the message. The fraction of execution s in which most nodes get the message depends on the gossiping probability a nd the topology of the network. In the networks we have considered, using g ossiping probability between 0.6 and 0.8 suffices to ensure that almost every node gets the message in almost every execution. For large networ ks, this simple gossiping protocol uses up to 35 % fewer messages than flood ing, with improved performance. Gossiping can also be combined with va rious optimizations of flooding to yield further benefits. Simulations show that adding gossiping to AODV results in significant performance improv ement, even in networks as small as 150 nodes. We expect that the improvemen t should be even more significant in larger networks. I.
Topology Control in Wireless Ad Hoc and Sensor Networks
 ACM Computing Surveys
, 2005
"... Topology Control (TC) is one of the most important techniques used in wireless ad hoc and sensor networks to reduce energy consumption (which is essential to extend the network operational time) and radio interference (with a positive effect on the network traffic carrying capacity). The goal of thi ..."
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Cited by 296 (4 self)
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Topology Control (TC) is one of the most important techniques used in wireless ad hoc and sensor networks to reduce energy consumption (which is essential to extend the network operational time) and radio interference (with a positive effect on the network traffic carrying capacity). The goal of this technique is to control the topology of the graph representing the communication links between network nodes with the purpose of maintaining some global graph property (e.g., connectivity), while reducing energy consumption and/or interference that are strictly related to the nodes ’ transmitting range. In this article, we state several problems related to topology control in wireless ad hoc and sensor networks, and we survey stateoftheart solutions which have been proposed to tackle them. We also outline several directions for further research which we hope will motivate researchers to undertake additional studies in this field.
Stochastic properties of the random waypoint mobility model
 Wireless Networks
"... Abstract  The random waypoint model is a commonly used mobility model for simulations of wireless communication networks. In this paper, we present analytical derivations of some fundamental stochastic properties of this model with respect to: (a) the length and duration of a movement epoch, (b) t ..."
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Cited by 202 (3 self)
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Abstract  The random waypoint model is a commonly used mobility model for simulations of wireless communication networks. In this paper, we present analytical derivations of some fundamental stochastic properties of this model with respect to: (a) the length and duration of a movement epoch, (b) the chosen direction angle at the beginning of a movement epoch, and (c) the cell change rate of the random waypoint mobility model when used within the context of cellular networks. Our results and methods can be used to compare the random waypoint model with other mobility models. The results on the movement epoch duration as well as on the cell change rate enable us to make a statement about the \degree of mobility " of a certain simulation scenario. The direction distribution explains in an analytical manner the eect that nodes tend to move back to the middle of the system area.
Stationary Distributions for the Random Waypoint Mobility Model
 IEEE Transactions on Mobile Computing
, 2003
"... In simulations of mobile ad hoc networks, the probability distribution governing the movement of the nodes typically varies over time, and converges to a "steadystate" distribution, known in the probability literature as the stationary distribution. Some published simulation results ig ..."
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Cited by 184 (7 self)
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In simulations of mobile ad hoc networks, the probability distribution governing the movement of the nodes typically varies over time, and converges to a "steadystate" distribution, known in the probability literature as the stationary distribution. Some published simulation results ignore this initialization discrepancy. For those results that attempt to account for this discrepancy, the practice is to discard an initial sequence of observations from a simulation in the hope that the remaining values will closely represent the stationary distribution. This approach is inefficient and not always reliable. However, if the initial locations and speeds of the nodes are chosen from the stationary distribution, convergence is immediate and no data need be discarded. We derive the stationary distributions for location, speed, and pause time for the random waypoint mobility model. We then show how to implement the random waypoint mobility model in order to construct more efficient and reliable simulations for mobile ad hoc networks. Simulation results, which verify the correctness of our method, are included.
The message delay in mobile ad hoc networks
, 2005
"... A stochastic model is introduced that accurately models the message delay in mobile ad hoc networks where nodes relay messages and the networks are sparsely populated. The model has only two input parameters: the number of nodes and the parameter of an exponential distribution which describes the ti ..."
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Cited by 144 (5 self)
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A stochastic model is introduced that accurately models the message delay in mobile ad hoc networks where nodes relay messages and the networks are sparsely populated. The model has only two input parameters: the number of nodes and the parameter of an exponential distribution which describes the time until two random mobiles come within communication range of one another. Closedform expressions are obtained for the Laplace–Stieltjes transform of the message delay, defined as the time needed to transfer a message between a source and a destination. From this we derive both a closedform expression and an asymptotic approximation (as a function of the number of nodes) of the expected message delay. As an additional result, the probability distribution function is obtained for the number of copies of the message at the time the message is delivered. These calculations are carried out for two protocols: the twohop multicopy and the unrestricted multicopy protocols. It is shown that despite its simplicity, the model accurately predicts the message delay for both relay strategies for a number of mobility models (the random waypoint, random direction and the random walker mobility models).
AntHocNet: An adaptive natureinspired algorithm for routing in mobile ad hoc networks
 EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS
, 2005
"... In this paper we describe AntHocNet, an algorithm for routing in mobile ad hoc networks. It is a hybrid algorithm, which combines reactive route setup with proactive route probing, maintenance and improvement. The algorithm is based on the Natureinspired Ant Colony Optimization framework. Paths are ..."
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Cited by 106 (16 self)
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In this paper we describe AntHocNet, an algorithm for routing in mobile ad hoc networks. It is a hybrid algorithm, which combines reactive route setup with proactive route probing, maintenance and improvement. The algorithm is based on the Natureinspired Ant Colony Optimization framework. Paths are learned by guided Monte Carlo sampling using antlike agents communicating in a stigmergic way. In an extensive set of simulation experiments, we compare AntHocNet with AODV, a reference algorithm in this research area. We show that our algorithm can outperform AODV on different evaluation criteria. AntHocNet’s performance advantage is visible over a broad range of possible network scenarios, and increases for larger, sparser and more mobile networks. AntHocNet is also more scalable than AODV.
Perfect Simulation and Stationarity of a Class of Mobility Models
 in IEEE Infocom
, 2005
"... Abstract — We define “random trip", a generic mobility model for independent mobiles that contains as special cases: the random waypoint on convex or non convex domains, random walk with reflection or wrapping, city section, space graph and other models. We use Palm calculus to study the model ..."
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Cited by 104 (3 self)
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Abstract — We define “random trip", a generic mobility model for independent mobiles that contains as special cases: the random waypoint on convex or non convex domains, random walk with reflection or wrapping, city section, space graph and other models. We use Palm calculus to study the model and give a necessary and sufficient condition for a stationary regime to exist. When this condition is satisfied, we compute the stationary regime and give an algorithm to start a simulation in steady state (perfect simulation). The algorithm does not require the knowledge of geometric constants. For the special case of random waypoint, we provide for the first time a proof and a sufficient and necessary condition of the existence of a stationary regime. Further, we extend its applicability to a broad class of non convex and multisite examples, and provide a readytouse algorithm for perfect simulation. For the special case of random walks with reflection or wrapping, we show that, in the stationary regime, the mobile location is uniformly distributed and is independent of the speed vector, and that there is no speed decay. Our framework provides a rich set of well understood models that can be used to simulate mobile networks with independent node movements. Our perfect sampling is implemented to use with ns2, and it is freely available to download from
ContentionAware Performance Analysis of MobilityAssisted Routing
 IEEE TRANSACTIONS ON MOBILE COMPUTING (UNDER SUBMISSION)
"... A large body of work has theoretically analyzed the performance of mobilityassisted routing schemes for intermittently connected mobile networks. However, the vast majority of these prior studies have ignored wireless contention. Recent papers have shown through simulations that ignoring contention ..."
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Cited by 96 (7 self)
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A large body of work has theoretically analyzed the performance of mobilityassisted routing schemes for intermittently connected mobile networks. However, the vast majority of these prior studies have ignored wireless contention. Recent papers have shown through simulations that ignoring contention leads to inaccurate and misleading results, even for sparse networks. In this paper, we analyze the performance of routing schemes under contention. First, we introduce a mathematical framework to model contention. This framework can be used to analyze any routing scheme with any mobility and channel model. Then, we use this framework to compute the expected delays for different representative mobilityassisted routing schemes under random direction, random waypoint and communitybased mobility models. Finally, we use these delay expressions to optimize the design of routing schemes while demonstrating that designing and optimizing routing schemes using analytical expressions which ignore contention can lead to suboptimal or even erroneous behavior.
Design patterns from biology for distributed computing
 ACM TRANS. AUTON. ADAPT. SYST
, 2006
"... ..."
Wireless Ad Hoc Podcasting
, 2007
"... Podcasting has become popular for dissemination of streaming contents over the Internet. It is based on software clients that query servers for updates of subscribed content feeds. Podcasting may be used for any media content, but it is most commonly associated with audio streams. It provides a sim ..."
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Cited by 74 (4 self)
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Podcasting has become popular for dissemination of streaming contents over the Internet. It is based on software clients that query servers for updates of subscribed content feeds. Podcasting may be used for any media content, but it is most commonly associated with audio streams. It provides a simple, nofrills broadcasting system for delay tolerant contents. A main limitation with this system is the inflexible separation of downloading to a docked media player and expending of the data when on the move. We herein present how podcast could be supported by our previously proposed delaytolerant broadcasting system in order to reduce the expected times between updates and to provide a new ad hoc podcasting mode among mobile nodes. Our system substitutes the clientserver paradigm inherent in present podcasting by a peertopeer paradigm where mobile nodes provide each other with contents. We present the protocol for this, and an evaluation of solicitation and caching strategies that greatly affect the applicationlevel throughput. Our design is aiming at simplicity in order to enable implementation in mobile phones with media players and other devices that communicate over short ranges by means of Bluetooth or wireless LAN.