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A Survey of Mobility Models for Ad Hoc Network Research
- WIRELESS COMMUNICATIONS & MOBILE COMPUTING (WCMC): SPECIAL ISSUE ON MOBILE AD HOC NETWORKING: RESEARCH, TRENDS AND APPLICATIONS
, 2002
"... In the performance evaluation of a protocol for an ad hoc network, the protocol should be tested under realistic conditions including, but not limited to, a sensible transmission range, limited buffer space for the storage of messages, representative data traffic models, and realistic movements of t ..."
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Cited by 1213 (8 self)
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In the performance evaluation of a protocol for an ad hoc network, the protocol should be tested under realistic conditions including, but not limited to, a sensible transmission range, limited buffer space for the storage of messages, representative data traffic models, and realistic movements of the mobile users (i.e., a mobility model). This paper is a survey of mobility models that are used in the simulations of ad hoc networks. We describe several mobility models that represent mobile nodes whose movements are independent of each other (i.e., entity mobility models) and several mobility models that represent mobile nodes whose movements are dependent on each other (i.e., group mobility models). The goal of this paper is to present a number of mobility models in order to offer researchers more informed choices when they are deciding upon a mobility model to use in their performance evaluations. Lastly, we present simulation results that illustrate the importance of choosing a mobility model in the simulation of an ad hoc network protocol. Specifically, we illustrate how the performance results of an ad hoc network protocol drastically change as a result of changing the mobility model simulated.
The Node Distribution of the Random Waypoint Mobility Model for Wireless Ad Hoc Networks
, 2003
"... The random waypoint model is a commonly used mobility model in the simulation of ad hoc networks. It is known that the spatial distribution of network nodes moving according to this model is, in general, nonuniform. However, a closed-form expression of this distribution and an in-depth investigation ..."
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Cited by 377 (10 self)
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The random waypoint model is a commonly used mobility model in the simulation of ad hoc networks. It is known that the spatial distribution of network nodes moving according to this model is, in general, nonuniform. However, a closed-form expression of this distribution and an in-depth investigation is still missing. This fact impairs the accuracy of the current simulation methodology of ad hoc networks and makes it impossible to relate simulation-based performance results to corresponding analytical results. To overcome these problems, we present a detailed analytical study of the spatial node distribution generated by random waypoint mobility. More specifically, we consider a generalization of the model in which the pause time of the mobile nodes is chosen arbitrarily in each waypoint and a fraction of nodes may remain static for the entire simulation time. We show that the structure of the resulting distribution is the weighted sum of three independent components: the static, pause, and mobility component. This division enables us to understand how the models parameters influence the distribution. We derive an exact equation of the asymptotically stationary distribution for movement on a line segment and an accurate approximation for a square area. The good quality of this approximation is validated through simulations using various settings of the mobility parameters. In summary, this article gives a fundamental understanding of the behavior of the random waypoint model.
IMPORTANT: A framework to systematically analyze the Impact of Mobility on Performance of RouTing protocols for Adhoc NeTworks
- IEEE INFOCOM
, 2003
"... Abstract — A Mobile Ad hoc Network (MANET) is a collection of wireless mobile nodes forming a temporary network without using any existing infrastructure. Since not many MANETs are currently deployed, research in this area is mostly simulation based. Random Waypoint is the commonly used mobility mod ..."
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Cited by 299 (18 self)
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Abstract — A Mobile Ad hoc Network (MANET) is a collection of wireless mobile nodes forming a temporary network without using any existing infrastructure. Since not many MANETs are currently deployed, research in this area is mostly simulation based. Random Waypoint is the commonly used mobility model in these simulations. Random Waypoint is a simple model that may be applicable to some scenarios. However, we believe that it is not sufficient to capture some important mobility characteristics of scenarios in which MANETs may be deployed. Our framework aims to evaluate the impact of different mobility models on the performance of MANET routing protocols. We propose various protocol independent metrics to capture interesting mobility characteristics, including spatial and temporal dependence and geographic restrictions. In addition, a rich set of parameterized mobility models is introduced including Random Waypoint, Group Mobility, Freeway and Manhattan models. Based on these models several ’test-suite ’ scenarios are chosen carefully to span the metric space. We demonstrate the utility of our testsuite by evaluating various MANET routing protocols, including DSR, AODV and DSDV. Our results show that the protocol performance may vary drastically across mobility models and performance rankings of protocols may vary with the mobility models used. This effect can be explained by the interaction of the mobility characteristics with the connectivity graph properties. Finally, we attempt to decompose the routing protocols into mechanistic “building blocks ” to gain a deeper insight into the performance variations across protocols in the face of mobility. I.
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 commu-nication 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 commu-nication 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 sim-ulation scenario. The direction distribution explains in an analytical manner the eect that nodes tend to move back to the middle of the system area.
Smooth is Better than Sharp: A Random Mobility Model for Simulation of Wireless Networks
, 2001
"... This paper presents an enhanced random mobility model for simulation-based studies of wireless networks. Our approach makes the movement trace of individual mobile stations more realistic than common approaches for random movement. After giving a survey of mobility models found in the literature, we ..."
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Cited by 167 (2 self)
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This paper presents an enhanced random mobility model for simulation-based studies of wireless networks. Our approach makes the movement trace of individual mobile stations more realistic than common approaches for random movement. After giving a survey of mobility models found in the literature, we give a detailed mathematical formulation of our model and outline its advantages. The movement concept is based on random processes for speed and direction control in which the new values are correlated to previous ones. Upon a speed change event, a new target speed is chosen, and an acceleration is set to achieve this target speed. The principles for a direction change are similar. Moreover, we propose two extensions for modeling typical movement patterns of vehicles. Finally, we consider strategies for the nodes' border behavior (i.e., what happens when nodes move out of the simulation area) and point out a pitfall that occurs when using a bounded simulation area.
Manet simulation studies: The incredibles
- ACM SIGMOBILE Mobile Computing and Communications Review
, 2005
"... Simulation is the research tool of choice for a majority of the mobile ad hoc network (MANET) community. However, while the use of simulation has increased, the credibility of the simulation results has decreased. To determine the state of MANET simulation studies, we surveyed the 2000-2005 proceedi ..."
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Cited by 164 (0 self)
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Simulation is the research tool of choice for a majority of the mobile ad hoc network (MANET) community. However, while the use of simulation has increased, the credibility of the simulation results has decreased. To determine the state of MANET simulation studies, we surveyed the 2000-2005 proceedings of the ACM International Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc). From our survey, we found significant shortfalls. We present the results of our survey in this paper. We then summarize common simulation study pitfalls found in our survey. Finally, we discuss the tools available that aid the development of rigorous simulation studies. We offer these results to the community with the hope of improving the credibility of MANET simulation-based studies. I.
Sound Mobility Models
- in ACM MobiCom
, 2003
"... and evaluation of mobile systems. By using mobility models that describe constituent movement, one can explore large systems, producing repeatable results for comparison between alternatives. Unfortunately, the vast majority of mobility models---including all those in which nodal speed and distance ..."
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Cited by 147 (2 self)
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and evaluation of mobile systems. By using mobility models that describe constituent movement, one can explore large systems, producing repeatable results for comparison between alternatives. Unfortunately, the vast majority of mobility models---including all those in which nodal speed and distance or destination are chosen independently--- su#er from decay ; average speed decreases until converging to some long-term average. Such decay provides an unsound basis for simulation studies that collect results averaged over time, complicating the experimental process.
Access and Mobility of Wireless PDA Users
"... In this paper, we analyze the mobility patterns of users of wireless handheld PDAs in a campus wireless network using an 11 week trace of wireless network activity. Our study has three goals. First, we characterize the high-level mobility and access patterns of handheld PDA users and compare these c ..."
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Cited by 142 (4 self)
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In this paper, we analyze the mobility patterns of users of wireless handheld PDAs in a campus wireless network using an 11 week trace of wireless network activity. Our study has three goals. First, we characterize the high-level mobility and access patterns of handheld PDA users and compare these characteristics to previous workload mobility studies focused on laptop users. Second, we develop two wireless network topology models for use in wireless mobility studies: an evolutionary topology model based on user proximity and a campus waypoint model that serves as a trace-based complement to the random waypoint model. Finally, we use our wireless network topology models as a case study to evaluate ad-hoc routing algorithms on the network topologies created by the access and mobility patterns of users of modern wireless PDAs.
A Mobility Based Metric for Clustering in Mobile Ad Hoc Networks
- In International Workshop on Wireless Networks and Mobile Computing (WNMC2001
, 2001
"... This paper presents a novel mobility metric for mobile ad hoc networks (MANET) that is based on the ratio between the received power levels of successive transmissions measured at any node from all its neighboring nodes. This mobility metric is subsequently used as a basis for cluster formation wh ..."
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Cited by 132 (3 self)
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This paper presents a novel mobility metric for mobile ad hoc networks (MANET) that is based on the ratio between the received power levels of successive transmissions measured at any node from all its neighboring nodes. This mobility metric is subsequently used as a basis for cluster formation which can be used for improving the scalability of services such as routing in such networks. We propose a distributed clustering algorithm, MOBIC, based on the use of this mobility metric for selection of clusterheads, and demonstrate that it leads to more stable cluster formation than the Lowest-ID clustering algorithm 1 which is a well known clustering algorithms for MANETs. We show reduction of as much as 33% in the number of clusterhead changes owing to the use of the proposed technique. In a MANET that uses scalable cluster-based services, the network performance metrics such as throughput and delay are tightly coupled with the frequency of cluster reorganization. Therefore, we believe that since using MOBIC results in a more stable conguration, it will directly lead to improvement of performance. Keywords: Ad hoc networks, Mobility, Clustering. 1
The IMPORTANT framework for analyzing the Impact of Mobility on Performance Of RouTing protocols for Adhoc NeTworks
, 2003
"... A Mobile Ad hocNcBV`D (MAN`D is a collection of wireless mobile nodes forming a temporary network without using any existing infrastructure. Since not manyMANB` are currently deployed, research in this area is mostly simulation based. Random Waypoint is the commonly used mobility model in these simu ..."
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Cited by 130 (12 self)
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A Mobile Ad hocNcBV`D (MAN`D is a collection of wireless mobile nodes forming a temporary network without using any existing infrastructure. Since not manyMANB` are currently deployed, research in this area is mostly simulation based. Random Waypoint is the commonly used mobility model in these simulations. Random Waypoint is a simple model that may be applicable to some scenarios. However, we believe that it is not su#cient to capture some important mobility characteristics of scenarios in which MANhB may be deployed. Our framework aims to evaluate the impact of di#erent mobility models on the performance ofMAN; routing protocols. We propose various protocol independent metrics to capture interesting mobility characteristics, including spatial and temporal dependence and geographic restrictions. In addition, a rich set of parameterized mobility models is introduced including Random Waypoint, Group Mobility, Freeway and Manhattan models. Based on these models several #test-suite# scenarios are chosen carefully to span the metric space. We demonstrate the utility of our test-suite by evaluating variousMANo routing protocols, including DSR, AODV and DSDV. Our results show that the protocol performance may vary drastically across mobility models and performance rankings of protocols may vary with the mobility models used. This e#ect can be explained by the interaction of the mobility characteristics with the connectivity graph properties. Finally, we attempt to decompose the reactive routing protocols into mechanistic "building blocks" to gain a deeper insight into the performance variations across protocols in the face of mobility.